Need Advice: Gear Lever moves even if Key's Out

[mr232]

I have a 1997 210 e50 (119 engine, 722.6 trans). I recently had the transmission replaced with a rebuilt unit.

All works well except that the park lock safety system seems to have been inadvertently disabled. Keys can now be removed regardless of gear lever position. Gear lever can now also be moved even with the key out. Park safety lock system was working well before transmission was replaced.

Would very much appreciate any inputs where to start (fuses, loose harness connections, etc.)? I will take it to back to the shop but would like to have an idea what went wrong. Thanks