Hello All,
I think I figured out the magic path to correct the issue.
I currently have iOS 15.4
I currently have gmail version 6.0.220306 (came out 3 days ago)
I went in to the iphone and my ipad setting, turned off notifications, then turned back on notification.
I went into the gmail app in my iphone and ipad and updated the gmail app. then I went into each and went to settings > the account > notifications > switch to None then back to All new mail > backed out then to Notification Sound updated to Welcome for both devices > backed out and closed the app.
Ive sent 4 test emails to myself from a different email and I received the badge notification instantly on both devices!
from what I was reading on other sites the Gmail tone Classic (which my ipad defaulted to) is no longer working, so I think doing a quick reset of my notifications to off then back on and selecting a tone of anything but Classic (which only shows on my ipad and not on my iphone as an option), and it worked like a gem!