Thank you for the responses.
I went ahead and tried removing the marketplace add on sceneries one by one, and initially was not able to get the pushback trucks visible. Eventually all of them were deleted, I signed out (I’m on Xbox), signed back in, and they were there! I’ve been testing at KSEA and KSFO.
A few minutes ago I tried again and now the pushback trucks are gone again. I don’t have any addon sceneries installed, only aircraft.
So frustrating. May try to do a clean install if that would help. These worked fine up until a month or so ago. Thank you again.