Typical pool store bull manure, because they have no clue but, don't want to tell you that. It is a fact of life that rubber gaskets deteriorate and start to do what you are seeing. If it is a problem, all you can do is replace the gasket. You may want to install a new gasket made of a synthetic material such as silicon. The downside is you will have to drain your pool below the level of the jet. You do not want to get water behind your liner.
BTW, in a vinyl pool, your CH could be 0 and it would not hurt anything.