I think Smitty might have hit on it. I cant believe I dont have a 21 UCL print at home! There are two ways you will open the door-
1. Automatically-arrival at the floor from another floor
2. Reopen-the car is at the floor and it opens due to the safety edge, door open button, car call or hall call
Sounds as if your auto open is working correctly, you just need to fix your reopen on hall button. 1DO-2DO or D1R-D2R are your doors relays-usually a Capacitor holds them up once they are set for a predetermined time. If you look at the print for your door logic it will show 2 maybe 3 distinct paths to pull in your open relays-one of these is most likely your culprit. If I had a print of a 21 UCL I could probably point you to it-hope this helps
