Notification doesn't show up on Redmi 8 MIUI 11 and 12 Some push notification from some apps (some games actually, I wasn't aware about other apps) suddenly no longer appeared. When I first bought this phone, they all worked fine, but then I updated MIUI to 11 and 12, and since then notification from games wouldn't appear. They would only appear when:

I opened the said games
In battery-saving mode (on low battery, when I activated this mode, notifs will immediately popped up)

I have turned on notification in Settings for those apps, doesn't help.
Anyone encountered the same problem? Any solution?
My device:
Redmi Note 8 Pro, Android 10 (Q), MIUI Global 12.0.2 Stable
This is usually a problem with battery optimization. Go to your settings and identify the list under battery optimization (that is the stock Android name, it could be battery saver etc). Remove those apps from the list
Edit: As confirmed by OP in comment, it is found under Settings → Battery &amp; performance → App battery saver. Selecting those app(s) from the list, and changing from Battery Saver to No restrictions fixed the problem of missing notifications.