Regarding the tempest test test_create_server_with_scheduler_hint_group_anti_affinity it does pass but it boots the two instance with a single requests[1]. This means there is a single scheduling attempt not two.
In my devstack the single request case works properly so I conclude that the tempest test does not exercise the same scenario that the reporter and I see failing.
Regarding the tempest test test_create_ server_ with_scheduler_ hint_group_ anti_affinity it does pass but it boots the two instance with a single requests[1]. This means there is a single scheduling attempt not two.
In my devstack the single request case works properly so I conclude that the tempest test does not exercise the same scenario that the reporter and I see failing.
[1] https:/ /github. com/openstack/ tempest/ blob/bcb6cc6184 b6c847f6e72305f 52b886835a6ca90 /tempest/ api/compute/ admin/test_ servers_ on_multinodes. py#L50