Using Outlook for iOS for personal email and calendar management
Only solution that worked for me so far is to delete the Outlook iOS app and switch to the native iOS Mail app.
iPad Pro 12,9 gen 4 with an Apple Magic Keyboard and I also tried using a Logitch MX Keys bluetooth keyboard. Everything updated to the latest firmware where possible. As soon as you stop typing for a few seconds the „focus“jumps away from the text entry area or the onscreen keyboard closes.
I guess the iOS suite of Office 365 it is not really a priority for Microsoft.
As a result I simply use the iOS Office suite as a 100% last resort when I have no internet connection. Othertimes I remote desktop (not using the Microsoft RDP app since that also comes with a load of comprimises and workarounds on keyboard, screen resultion) into my main workstation.