No, it is not a duplicate of HHH-8488 Closed as that regards treated joins and this one is about treated roots. It seems similar to HHH-11081 Closed but it is not fixed by the resolution for that issue as my testcase still fails.

In https://github.com/hibernate/hibernate-orm/pull/1725 I add two testcases, one for HHH-10767 Closed (which helped me determine that that one was already fixed) but also one for this issue which still fails/failed on current master. The fix for this issue ( HHH-10561 Awaiting Response ) is also in that pull request, with that fix the testcase does not fail anymore.