I've noticed this a couple times in the previous snapshots, but it is so hard to replicate.
I have figured out the cause of the issue and replicating it is quite easy.

The bug:
It might be intended that the Warden stops chasing a suspect if the anger value of that suspect goes below 80, but it creates very odd cases where the Warden can roar at a suspect and then stop chasing the suspect it just roared at. This happens when the anger value of a suspect just barely goes above 80 which is the threshold for making the Warden roar and chase a target.

Steps to reproduce:

• Create a wool area so that vibrations can't be detected by using the command below
  /fill ~-10 ~-1 ~-10 ~10 ~5 ~10 minecraft:white_wool hollow

• Create a scoreboard with the commands below
  /scoreboard objectives add WardenAnger dummy
  /scoreboard objectives setdisplay sidebar WardenAnger

• Inside of a repeating command block that is always active, enter this command.
  execute as @e[type=minecraft:warden,limit=1] at @s store result score AngerLevel WardenAnger run data get entity @s anger.suspects[0].anger

• Create two separate fenced areas like seen in this screenshot
  

• Summon a Warden in one of the fenced areas and zombie in the other

• Observe the Wardens behavior and anger value

Observed Results:
The Warden can sometimes, very inconsistently, roar but not chase the player/mob

• The suspects anger value can barely go over 80 (which is the threshold for the Warden to roar and start chasing a target), and then quickly go below 80 which causes the Warden to stop chasing the suspect it just got angry at.
• All suspect data gets erased once a suspects anger value goes below 80 Fixed in 22w15a

Expected Results:

• The Warden will continue to chase the suspect it just got angry at for a normal period of time, and then proceed to roam once the anger value of the suspect goes below 80.
• The Warden's suspect data will not be erased once the anger value of a suspect goes below 80. Fixed in 22w15a

A possible solution
A possible solution could be to set the anger value to it's maximum value once a suspects anger value goes above 80. (I believe this value is 150 because no matter how many times I hit the Warden it never goes above this value). This will cause the Warden to chase the suspect for a normal amount of time. Once the suspects anger value goes below 80, that suspect will no longer become the target and the Warden will start looking for more suspects.