you can. no issues. ive gone from g935p to g935u and back. if i were you id stay on g935u...no bloat and Sprint loves to bloat. thats why our updates take so long.
I have the G935P internationally unlocked and am currently using it on Att, but I have many issues with voicemail and once it looses signal it will not regain it on its own I have to go to airplane mode then back on to find signal again. I have the MSL code for the phone as well and tried arranging the bands for ATT but it is not listing a couple of Bands that ATT uses. Will flashing my G935P to G935U firmware give me that option and the control I am looking for?