Windows App (RD Client) Credentials Problems Windows 11?

I have used the MS RD Client App (now Windows App) for years, with a the occasional log-in issue, but mosly without problems.

I recently started to use a new Windows 11 PC. I was initially impressed with how easily RD Client connected to the new computer but then the problems started and the App was unable to log into the PC.

I created a new local user (not linked to a Windows account) and that failed too, until I turned off all auto correct, shortcuts etc in the iPad Keyboard settings. This is probably an acceptable work-around but I wondered if anyone else had experiened this sort of problem. It seems to be some sort if caching problem (somewhere) or iPad keyboard option is causing problem.