issue since upgrade to Ventura

Hello msperkins,

First, close the Mail app on your iPhone, restart your iPhone and test the issue again. These simple steps often fix minor issues.

Close an app on your iPhone or iPod touch

1. "From the Home Screen, swipe up from the bottom of the screen and pause in the middle of the screen.
2. Swipe right or left to find the app that you want to close. 
3. Swipe up on the app's preview to close the app."

Restart your iPhone - Apple Support

If that doesn't fix the issue, it might help to remove the account from both devices then add it back again. this will clear out any error the accounts may have encountered. You can find more information about adding an email account to your devices below:

• Add an email account to your iPhone, iPad, or iPod touch
• Add an email account to Mail on your Mac

If you continue to experience issues after removing the account and adding it back or if the issue is only with your Gmail account, we'd recommend contacting Google directly for assistance.

Cheers!

I also experienced this problem after an upgrade to Ventura. Deleting and reinstalling the gmail account on the iPhone solved the problem: on iOS 16.1, go to Settings / Mail / Accounts / Gmail. Press Delete Account, let it finish, then add it in again in the same place. Of course, you will get the usual security confirmations.