My Galaxy S9 phone received some post-end-of-support system update in August 2022 that broke push notifications for most of the installed apps.
The only apps that still receive notifications are Samsung apps, Telegram messenger and Gmail. Samsung apps keep receiving notifications as well as they did it before the update. Telegram receives them too. Most of the other apps (like Google Photos) don't receive notifications at all, and those few of them that are still able to receive notifications (like Gmail) receive them with several hours delay. I've tried disabling all kind of battery optimizations for the apps, clearing apps' cache and data, reinstalling apps anew, adding apps to the list of apps that won't be put to sleep, turning apps' notifications off and on, disabling phone power saving mode, switching internet connection but had no success.
I've tried troubleshooting the problem with the developer of the one of the apps that were affected and he said that he sends push notification to google service messaging system but the phone does never receive it, acting as if its offline.
I'm quite sure that notifications were broken by the August update as the problem occured right after the update installation. Is there any chance this problem would be fixed?
Hah! This option is always on the table. Though I still hope there's less costly way to fix this issue.