Hi Detlef.
Thank you.
Will trying to downgrade to 31.0.1 or 30.0.5 again.
Had also tried to downgrade this morning, with SDK manager by removing SDK 31, reinstalling SDK 30 / platform tools. But it always installs platform tools with version 31, nevertheless only SDK 30 is installed.
Edit: With Platform Tools 30.0.5 (separately installed) it works.