I have the stoner as well and a few others. I have found with the 938, while practice drawing, unless I have a really thick belt on, the holster comes right out with gun.
I have 3 that I use. If I want max comfort I opt for my N82 pro model IWB, for deep concealment I use my "On Your Six" kydex IWB and a for ultimate comfort it's a OWB Desantis leather. All 3 are great holsters depending on what flavor I want that particular day.