The movement of SODE jetways are limited to constraints that were set up in the modelling stage. So it is not a matter of AFCAD radius setting. The jetway model would have to be re-built with more range for the up and down motion for the “door too low” case. But I am pretty sure that the PMDG737 works on other stands, maybe for the particular stand you used the combination of jetway position and aircraft position/heading was crossing the geometrical limit of the jetway.
I have sent an updated model to PacSim and it is being tested currently. If the new model is able to serve the PMDG737 more better, the fix will be available through PacSim’s website.