Dirty Donuts are so Good.
Usually failure to feed, but not all that often. But often enough that I couldn't shoot reloads in any informal competition events, not without the time penalty of clearing malfunctions. I suspect the great accuracy of the P365 is partially due to a minimally dimensioned chamber. I would not hesitate to shoot reloads in target practice if the malfunction rate was low. YMMV
Of the 2,500 rounds I put thru mine, I might mention none of them were reloads. But I did shoot a ton of WWB and BB and various HP’s.