I don’t know your coach specifics or the kind of bed system you have but just a “guess” that perhaps your bed lift mechanism motors are slightly out of sync so one side of the bed is not fully in the correct up position to allow its pin to be inserted. If its a LCI system their motor resync process is below (taken from their manual) but again I don’t know which system you have etc so this may not be your issue. Just like for slides the LCI motors need to have the up/down or in/out switch held a few seconds longer after the motion stops. Hope this helps.
Resynchronizing the Motors
1. Fully raise the bunk lift using the switch. Keep the switch engaged until the motors shut down on their own.
2. Lower the bunk lift 1-2 inches.
3. Repeat steps 1 and 2 until both motors shut down at the same time. In many cases, two or three repetitions are necessary to re-sync the system.
4. Fully raise and then lower the bunk lift. Again, always let the motors shut down on their own before releasing the switch.