Ha! So actually I was just about to post that. I followed my bug report trail, it linked to an identical issue in another app and suggested uninstalling the updates for WebView. Took me a bit to find it in My Apps because I was looking for "WebView", not "Android WebView" (you know the whole 'opposite end of the alphabet thing). But yes, did that, and now both GMail and the MLB Ballpark app are working fine (which is good because i have 3 tickets for a Cubs game in the Ballpark app)
Thanks for helping figure it out! I'm glad they are working, I'm absolutely loving the visuals of Android 12, as well as being able to tap on the Wifi button in Notifications and get options instead of turning off my wifi!