From all my years working in IT I've never had a good experience with the iOS/macOS mail app for either Exchange or Gmail, things break constantly. You're much better off using the proper Gmail or Outlook app.
Very strange. I've been using both iOS Mail and macOS mail with my company's Microsoft Exchange server for almost a decade with zero problems.
I've also been using both iOS and macOS with Gmail on my personal account for close to 20 years across close to a dozen computers and devices, and the only problem I've ever had is when Gmail suddenly decides to let some company bypass its spam filter.
I think I use Gmail's web interface maybe two or three times a year.
One particular well documented issue that first cropped up about 5 years ago that I still see to this day is the spam of calendar invite acceptance e-mails (so much spam that the user gets outbound blocked). Only happens if the user accepts a calendar invite using the iOS calendar client, MS couldn't identify an issue and Apple didn't wanna hear about it.