Version 2.1 (beta?)
Edition Windows 10 Pro; Version 22H2; Installed on 2020-07-26; OS build 19045.3208; Experience Windows Feature Experience Pack 1000.19041.1000.0
In recreating the problem, I see it is caused because of the (new) setting "Only allow windows from the same application to be put in a group using drag and drop unless the shift key is held down" which is set.
So problem solved, thanks