Did you ever find an answer? I am having the same issues with delayed notifications or none at all. I have an iPad (7th gen), iphone 10, iphone 12.
Notifications have never worked on my 12 or ipad but they worked on my 10. I use both phones all of the time for different things, I typically have them both and it never really bothered me. Mostly laughable that my 10 would get instant notifications and my 12 would not get them or get them hours later. I also occasionally get notifications spam. 50 email notifications all at once. Sometimes when I open the actual apps - it works most of the time it doesn't.
I made the mistake of up restoring my 10 and since notifications do not work.
Both phone were originally on sprint sim cards- 12 has been updated to tmobile.
Ipad is wifi only.
Everything has been done- resets, restores, carrier settings, individually turning notifications off restarting, turning back on. DND/battery, deleting/redownloading enabling push from app.
Every once and while it annoys me enough to where I scour the forums hoping someone has fixed but at this point, nothing has worked.
Today, I got an apple pay notification at 230pm est. This transaction occurred on Wednesday at 830am est.
I finally called Apple, at the very least, theirs shouldn't be delayed. Honestly, Apple people were great, suggested that I erase my ipad and start over with a new appleid. I did and the problem persists. 3 devices, 2 differnt OS and 2 differnt appleIDs have the issue. Gentleman said he was baffled. Anything I missed? Anything else I can do?
Now that my 10 doesn't give prompt notifications...I'm hating this.