I refrigerate mine all the time. I’ve never had a problem until this past weekend with sweating but after about an hour, it dried out and was fine. (I put a low fan on it for awhile to help it out).
I did have one issue with gum-tex added to fondant on the bill of a baseball hat. I stored it a rather humid walk-in at my kitchen and it completely collapsed. The SI gumpaste however did just fine. Those are my experiences, HTH!