comparators has got a bug after 1.20 update. I can't explain with texting so this video will explain you
[media]
MCPE-174123
problem with comparators
Resolved
Invalid
0
(Unassigned)
Unconfirmed
Multiple
1.20.12 Hotfix, 1.20.13 Hotfix, 1.20.14 Hotfix
Retrieved
Thank you for the video to explain the issue. The behavior you expect, that you say occurred before 1.20, is how comparators work in subtract mode. The comparator in the video is not in subtract mode. You can toggle the comparator mode by right-clicking or pressing the “use” button on it. When the comparator is in subtract mode its front torch will be lit.
You can read about comparator function here: https://minecraft.fandom.com/wiki/Redstone_Comparator?so=search