I think you are confusing the updates: the 1.3 update is one thing, but there was *another* small update after that, which is not applied if you don't check for it, or wait 24 hours since the last update.
I've just checked the described situation at PHNL, Gate 11 with the PMDG 737-800, and boarding ends normally, both loaders go back to their starting positions when they are done. No difference if I start requesting catering first, or go directly to boarding, works in both cases.