Ok, so it's only happening with 3rd party SODE jetways, we'll check it. In the meantime, just undock jetways manually.
However, it's not clear exactly what your problem is, because the subject of this thread is "customize menu stuck and ground handling not adaptable", while in fact it seems the only problem you are really having is that 3rd party SODE jetways are not undocked automatically if they are still attached when you start the next activity.