Usually issues at pick ups. The passenger isn't there, ready and waiting by the kerb side, ready to get in the car when you pull up. You may be expected to wait on a red route during enforceable hours, with a risk of getting a ticket. Sometimes the GPS position is wrong on either your phone or the passenger's phone, so they're where the app says they should be. Finally, if they're at the pick up point when you arrive, they're either in an unsafe, or an illegal spot (e.g. on zig-zag lines by a crossing).
Marios got a reaction from Zaven in Very quiet satudary on Halloween weekend