Possible regression 5.6 to 6.1 - [SqmRoot not yet resolved to TableGroup]

I will create a Jira issue for this yes (do I need some entitlements to do that?).

No, you just go to https://hibernate.atlassian.net/ and after registration you create an issue.

With your last addition the query works, but the statement is wrong:

What do you mean by “wrong”? Looks ok to me. Note that count(1) is equivalent to count(*) semantically.