@Ubi-Keo
I just tried to make a video in the past minutes : I've been unable to document 'Red Highlight' issue exclusively (and the new TU 1.6.1 requirement = being at, or less than, 8 meters from the Reda's Target) :

here what happened during my short gameplay :

1° Reda's camera shake (not included in the 15 min of game)

• after taking the quest at Reda and a fast travel with no issue > > 15 min of game gave this =

2° Red Highlight issue (worst now with Reda's targets = seems that now you have to be at least at 8 meters (or closer) from the target to trigger the 'Very little Red Highlight' )
3° XP issue with 'Reda's targets and friends' (already previously reported)
4° Red Highlight issue with 'Avenge Quest's Targets
5° XP issue with 'Avenge Quests Targets and friends' (already previously reported)
6° 'Close Camera Option' & 'Off-Center Camera Option' bugged when hooded (already previously reported)
7° Assassination from corner provoquing a weird off camera bug that will be fixed for the playthrough by quitting the game (already previously reported : the Game Team hasn't been able to reproduce it, too)
8° Eivor stuck for a really short time following a bow use, but enough to ruin what you planned to do, or to block a 'R1 / PS4' use. (this issue : texture collision after using a bow, mainly hunter bow, exist since day one)
8° 'False R1 / PS4' prompt (exist in the game since day one), I already previously documented the 'False R1 Prompt' alongside with the 'Reda's Target Red Highlight issue' in this video here : spoiler

Note : on the purpose to spare some space and time I volontary omitted to document in today's videos, the Camera shake when talking to Reda ('motion sickness issue' which was supposed to be resolved, or at least partially fixed, and that happen's, using TU 1.6.1, each time you talk to Reda).
Not being sure that the Game Team are able to reproduce the Red Highlight issue (that's really hard to believe that's is unreproducable) I also omitted to upload the newest videos to YTube (to save several hours of upload and to avoid having the whole home bandwith reserved to uploading them during this process).
if it is really needed I can send the Game Team a 'Full Step byStep How To' (thus, I doubt that they will appreciate a 'Full detailed How To Get and see the Red Highlight issue on PS4 pro' made by a noob like me)

As a reminder, this is how it was supposed to be working (I supposed that was working this way for any kind of ennemy) :

Assassin’s Creed Valhalla: Bringing Accessibility to a Viking Epic
Assassin’s Creed Valhalla’s focus on accessibility has been revealed today, joining Watch Dogs: Legion and Immortals Fenyx Rising as part of Ubisoft’s most accessible lineup of games to date. Assassin’s Creed Valhalla has many core gameplay features, as well as a bevy of customization options designed to improve both usability and accessibility for players.
We spoke with Maimouna Brownrigg, user interface team lead at Ubisoft Montreal, and Franck Murcia, user experience director at Ubisoft Montreal, about these features and options and how the team set out to improve accessibility in Assassin’s Creed Valhalla.

FIRST-TIME USER EXPERIENCE FLOW
A core set of options is available to all when booting up the game for the first time to enable a smooth experience from the outset.

CONTROLS
"We’re pretty proud of the ‘multiple methods to navigate menus’ option,” says Brownrigg. “Even as the developers, we realize how the free cursor was frustrating in some menus. We’ve been thinking about this since Assassin’s Creed Origins, so we’re pleased that we’ve been able to achieve this. But just having several ways for users to navigate ultimately benefits everyone."
"For controller remapping, we had a good foundation with Assassin’s Creed Odyssey as well,” says Murcia. “The team has tried to improve some aspects of it, and we’ve also added things like being able to swap [the left and right] sticks, which was a community-requested feature."
Multiple Methods to Navigate Menus
In addition to the free-cursor and mouse navigation in menus, there will be an optional “Focus” mode that snaps the cursor to menu items and enables navigation with the left stick or WASD on keyboard. (Motor, Vision, Cognitive)
(NEW) Addressed an issue where Layla's laptop couldn't be navigated with Focused navigation. (Motor, Cognitive)
(NEW) Sliders in menus may be controlled with left/right arrows on keyboard or the left stick on controllers. (Motor, Vision, Cognitive)
(NEW) In PhotoMode effect values may now be adjusted with arrow keys or WASD on keyboard. (Motor, Vision, Cognitive)
Control Remapping & Customization
There will be remapping for keyboard, mouse, and controllers. There are many complementary settings to customize controls (see list below). (Motor, Cognitive)
Invert controls for camera, movement, and raven
Swap sticks for both gameplay and menus on controller
Sensitivity for camera/movement on controller and mouse
Mouse acceleration
Left-handed mouse
Vibration (Off, Light, Full)
Auto (On Foot) movement (PC & keyboard/mouse only)
On PC, you can fully disable either controllers or keyboard and mouse.
Vibration
(NEW) Vibration on controllers has been adjusted and balanced post launch to address issues where it was too sustained or strong. (Motor, Cognitive)
Force Trigger Feedback for Weapons
(NEW) Force trigger feedback for combat (Xbox Series X|S or PS5 Only), and specific feedback for bow shooting mechanics was added. (Vision, Cognitive, Hearing, Motor)
Several Alternatives for Hold Inputs
There will be alternatives for many hold actions (Motor, Cognitive)
Aim toggle
Two-step confirmations in UI instead of hold
Weapon wheel toggle
Hold Alternative for Menu Interactions
There is an option to enable pop ups instead of holds in menu controls. (Motor, Vision, Cognitive)
(NEW) This was updated to address an issue where the memory stream couldn't be slected when starting a New Game. (Motor, Vision, Cognitive)
Hold Length Adjustment for Interaction
You will be able to adjust the length of interaction holds from 100-1,000 milliseconds (0.1-1 second). (Motor, Cognitive)
Quick Time Events
You will be able to choose between one-time press, hold, or repeated presses for quick time events. (Motor, Cognitive)
(NEW) An option was added to bypass QTEs entirely in some boss encounters - the additional setting is OFF in the options menu. (Motor, Cognitive)
Aim Assistance
There will be three levels of aim assistance for the bow. (Motor, Cognitive, Vision)
GAMEPLAY
"For an open-world game, you have a lot of components that are a part of the experience, and we thought it was natural to allow the player to really tweak those three aspects – fighting, stealth, and exploration – of the game," says Murcia. "We also added a small tweak to the gameplay for some cognitive feedback that helps you assassinate targets [with a guaranteed assassination]. It’s a small option, but it’s big for players who are struggling with stealth or are getting frustrated."
Screen Shake Toggle
You will be able to disable screen shake effects during gameplay. (Motion Sickness, Headaches, Vision)
Fight Difficulty
There will be four settings to customize the challenge of combat. (Cognitive, Motor, Vision, Hearing)
Stealth Difficulty
There will be three settings to customize the challenge of stealth. (Cognitive, Motor, Vision, Hearing)
Exploration Difficulty
There will be three settings to customize the challenge of exploration. (Cognitive, Motor, Vision)
Guaranteed Assassinate
Regardless of the difficulty setting selected, this setting enables you to always assassinate higher-level enemies. When this feature is off some higher-level enemies will only be partially damaged by assassination attempts. (Motor, Cognitive, Vision)
Secrets are Revealed when Syncronizing Viewpoints
(NEW) Secrets won't have to be manually found if a viewpoint is synchronized for an area for all difficulties except Pathfinder. (Cognitive)
Full Progression and Gameplay Customization
From choosing skill tree progression and ability upgrades to putting together diverse weapons, tools, and armor loadouts, you will be able to customize your playstyle to suit your individual strengths. (Motor, Vision, Cognitive)
Automatically Assign Unspent Skill Points
(NEW) An option is available from the center of the skill tree/fate. (Cognitive, Vision)
Odin's Sight
Odin’s Sight is a scan ability that will both identify and tag nearby loot and enemies with audio and visual cues. To enable further visual cues for Odin’s Sight, turn on Closed Captions (see Audio). (Cognitive, Vision, Motor)
(NEW) Odin's Sight radius increased and enemies will remain highlighted for longer. (Cognitive, Vision)
Tagging Enemies
When enemies are tagged with Odin’s Sight, there will be an outline and highlight on them. (Vision, Cognitive)

quoted from :
https://www.ubisoft.com/en-us/help/assassins-creed-valhalla/gameplay/article/accessibility-features-available-in-assassins-creed-valhalla/000079358

I re-did some new testings today :
mandatory distance to Highligh a Reda's target is completely erratic (9m for one of the Reda's Target, a bit more than 20 meters for the Reda's Weekly Target

I will ommit the several issues encoutered during these today's 30 min (including the time spent to test this erratic game behaviour aswell as encountering some other ones) of gameplay
Today would have been a good day for the game team to perform some tests :
2 Reda'S Daily contracts + 1 Reda's Weekly contract

@Ubi-DeskLamp
Many thanks to you for this update and for the forward

"Odin's Sight is inconsistent when highlighting enemies and with detection distance" : no change with TU 1.6.2

PS4 pro / Latest Firmware
AC Valhalla TU 1.6.2 / internal SSD
Manual Cloud Save Done