Phone screen randomly locking while using an app

Since last week, I’ve noticed this weird thing where I’m just using an app and the phone screen randomly locks itself, no clue why.

I double checked my display settings and nothing seems off on that front.

I have noticed that this tends to happen on Meta apps (WhatsApp, Instagram, Facebook), so I’m not sure if this is a phone issue or with those apps.

Anybody else in the same boat as me?