When you have everything buttoned up...when you first arm the vehicle...look at the DWA red status LED to see what it is telling you.
If it is flashing rapidly for the 1st 10 seconds...you may have an open monitor. BTW, it takes approx 20 seconds for the IMS (interior motion sensor) to arm after locking the vehicle. This allows anything that may still be moving inside the vehicle to settle down before the IMS does it thing.
Also, if you had the windows down when you armed (& locked) the vehicle....as you walked/moved by the vehicle...this can set-off the IMS (see info below about the IMS).
And make sure that the driver's door lock cylinder is lubed up...you mentioned that you had to crawl into the vehicle. The driver's door lock cylinder has a MANUAL unlock position that should work regardless if the car has power or has been locked electronically using the remote key. Again, if it is not allowing you to turn 90° counter clockwise...then spray some lube into the lock cylinder and let it "marinate" a few minutes...then make sure that it can turn to the manual UNLOCK position.