Realme GT Neo6 SE. Notifications are not received unless an app is running in the background. China ROM, Android 14

Hello!
I've got my hand on a new phone, everything works fine except for the notifications. I do not get ANY notifications from the app unless I open an app, then its notifications start popping either instantly or after a delay, which can vary. Sometimes the notifications show up after like 30 minutes (!).

I've checked the settings and made sure they are enabled for each app. "Wake screen when a notification is received" is also on.
I also disabled battery optimization. Nothing helped so far.

Any idea how to make them work properly without resorting to fiddling with the ROM? I would appreciate any help.

UPD:
Found a temporary solution that doesn't satisfy me. Going to Apps -> Auto Launch and enabling some apps there fixed the issue, but i cannot enable more than 5 apps...