Well, assuming up calls aren’t lighting up without physical button demand, I’d look at wire pins or worn relay components (N.O.-N.C. stationary contacts) in the following areas;
Up call cancel/stopping circuit, hall and car.
Selector relay contacts, directional relays as well.
The down arrow issue might be the relay that supports the voltage to the arrow itself.
Hopefully you have composite prints to help you track the areas you need to cover.
If you have access to a relay checker, that would be a big help.
Be careful inserting the relays back onto the relay base as those stupid copper base contacts will fold over.
