So I don’t want to jinx things but emails seem to be showing up in the email list promptly. We’ll see how it holds up.
**EDIT**
FAIL! It’s still not loading some emails Into the list until I open the app and it eventually does a refresh within the app.
Why isn’t the email being loaded to the app’s list at the same time the notification is received? It’s like it has to do a SECOND refresh to get the email into the list.
So I don’t want to jinx things but emails seem to be showing up in the email list promptly. We’ll see how it holds up.
**EDIT**
FAIL! It’s still not loading some emails Into the list until I open the app and it eventually does a refresh within the app.
Why isn’t the email being loaded to the app’s list at the same time the notification is received? It’s like it has to do a SECOND refresh to get the email into the list.
I was now out of possible solutions that I wanted to attempt on my own, so I resorted to contacting Apple. ... Last night, without me having to pay Apple a penny, I received great support. Shawn came on the chat after I waited a couple of minutes, and, after confirming everything I did, and talking to a senior advisor, told me the only path was to restore the iPhone using the backup on my computer. I didn’t want to do that much work, but that being the only option, that’s where we went.
...
Thankfully, after restarting the computer, iTunes recognized my iPhone, so I could proceed to restore and reload the backup. It took several hours, but now Mail works, as does everything else I’ve tried so far.
....
I always hate the idea of nuke and restore, just because of the time that it takes, but it maybe worth a try in your case. (Just make sure that you don't let iTunes install 13.3.1 over your beta version or you won't be able to restore.)
Nuking the phone won’t fix this issue. It has persisted between two different phones. I had an XS Max and had the issue and when I got the 11 Pro Max it was a completely new set up from scratch, not a backup and it still had the issue.
It is a well documented issue if you look around.