I've had the exact same issues with multiple Galaxy devices as well. I have no battery saver settings on, I've given certain apps that have delayed notifications unrestricted background access, and I have tried every possible solution, yet the problem persists. I was hoping the S22+ would be different but it's just more of the same. The only thing I can think of is there something fundamentally wrong in Samsung's software regarding background usage and notifications. Hopefully in the future they create an update that can help with this.
Did you ever get resolution to this matter? I am also getting delayed notifications from MyQ when the phone is locked. I called Samsung and was told there is not a setting on the phone which delays text notifications when the phone is locked. The tech ran a bunch of diagnostics which he said could contribute to the delay - RAM usage was high because several apps were open.
I have this exact same issue with my Galaxy S22+. My Galaxy S9 Curve did NOT have this issue. Text Messages, Alarms and Ring alerts seem to come in ok, but I have an app that provides a notification every 2.5 hours to eat or take medicine, that worked fine on my S9 that is having this issue on my S22+. If I have used my phone recently, the alerts come in on time (10 minutes till, 2 minutes till, right at time, and a 5 and 10 after). I have this app set to "Never Sleep" and it still ignores these unless the phone has been unlocked recently. Has made me miss multiple eating times. Same as OP, I have checked all of the above. Some other apps also appear delayed, such as Life360, Emails, and a few games that I allow notifications on.
Happened to me using Samsung A03 that is still on Android 11, as the phone is used for my new store, my Grab Merchant (an app for receiving order from Grab app) and Tokopedia Seller app (an online marketplace app for receiving order) are only receiving notifications (chats and orders) ONLY when I press power to have the display on. If the display is off, there is no notification at all.
I am quite knowledgeable to Android as Samsung A03 is only a phone I use for my store, my main phone is Asus ROG Phone 5s and this does not happen to it.
After few days testing (this has happened from the day I used A03 for my new store starting 23 March 2022 until today 15 April 2022 as I have the time to test it now), I have found solution to this problem thanks to this guide:
The main helpful solution from that web is the "Battery Optimization" / "Optimize Battery Usage" part. Once I set the App I need (the Grab Merchant and Tokopedia Seller), the notifications for these 2 Apps are working normally now.
