product with staff members (one unavailable) and inventory more than 1 not working fine

To reproduce try this example. User AXIS T23 is available for 08.10.2020 but user AXIS A22 is not. product Inventory is 5 (min:1, max:2).

Staff AXIS T23 is available so I booked 1 slot on 08.10.2020 at 18:00. There should be now 4 slots left on that day and time, but there aren’t.

What fixes it, is to remove the rule for the other user AXIS A22 for that day. Or to set staff AXIS A22 as the first staff.