EDIT, SEMI-FIX: switch to LTE Off. Cons - higher Latency(at times, not too many though, can seem like a cannot connect) & HSPA(or lower) vs LTE. Calling voice quality suffers / streaming can stutter at times. Pros - zero-INFREQUENT disconnects. Phone just loses network after extended period of non use OR just a couple of minutes inside pocket. Not using stock battery saver or any third party tweaker of any kind. A simple Airplane Mode off / on toggle fixes this. FYI toggling Data off / on does NOT fix this. I've ťried Data Always On + enabled Roaming Data to no avail. It's more annoying than concerning because Data is blazing fast on this phone. I've had this on previous phones and have fixed by creating new APN with T-mobile settings instead of Metro, PLUS adding all network Types BUT removing Hipri. Our present APN has new, different settings though, plus at this juncture System is not writable.