I tried your suggestion but I can't get the notifications to work.Uninstall everything from your device (microG+revanced) > reboot your device and your rooter (not necessary but if possible do it) > install latest Vanced MicroG by inotia00 > Install ReVanced or Extended > login. Go to Battery Optimization settings on your device and exclude microG for being optimized.
Let me know if you have any issue with notifications afterwards.
My setup:
• OnePlus 8 Pro running OOS 13
• MicroG v0.2.27.230755
• YouTube Revanced (extended) installed via Revancify v18.17.43
• Battery usage: foreground and auto launch allowed for both
• Notifications allowed
Any suggestion?