I'll leave it all apart for now in case someone comes up with a magic solution

Chris, if you do get a chance to look at yours can you let me know if you think there is anything that might be preventing it from manually unlocking. It looks like there is a motor as well as the microswitches in the module so I'm wondering if the motor hasn't reached a full position and the microswitch isn't talking to the convenience unit

That in turn may be preventing the mechanical side from operating

Going to dig out the wiring diagrams and peruse them in the meantime.