valputt,
Frozen dough has to be handled properly to get the best results. It would help to know how you manage your dough balls from the time you get them from your supplier to the point where they are shaped and dressed. There are many causes for bubbling but perhaps the most common is a dough that is too cold at the time of shaping. But, since there can be many potential causes, it would help to have more detail to be more certain.
Peter
