I'd bet you a box of cookies you might be having a Touchwiz issue (the native launcher in android). With TW, I couldn't access my Note4's camera settings, they would flash for a half second, then poof... gone! I couldn't run DJI's fpv drone apps either, typically unable to even see the login screen required to activate them (same half second flash of the screen). This was with both the older GO and newer GO4, and on multiple android devices (including 2 different Tab4's, 8' and 10' from ATT). They all run GO/GO4 flawlessly now.
I looked at probably 4 or 5 different launchers on the play store, and ended up with Nova Pro after an hour of checking out the totally free version. Best $4+ I've ever spent on a phone no doubt. Not only did it fix every weird issue I was previously having, it sped up my overall performance by 4x, easily.
For the record, I have nothing to do with Nova in particular, aside from being a beta tester. I'm super picky, and like what I like, same with everyone else. For me, it gave the best options of the ones I tried, and the dev team are pioneers in the launcher game, second to none. Even on beta versions, I haven't had a single glitch in over 6 months of phablet bliss. Trust me, if anyone can find a bug, it'll be me!
Ya gotta admit, spec wise, the Note4 was definitely ahead of its time, and still holds up against its $1000+ competitors (IMHO anyway). For the $225 I spent on mine that was 2 years old, I can't find one reason to upgrade it anytime soon. After snagging a new, decent quality battery, I've seen up to ~70 hours between charges... what more could one want? With an awesome 16mp cam, AMOLED display, micro SD slot, removable battery and quad cpu's, I wouldn't trade for any version of Note thats come since... even for free.
Best of luck, and long live the Note4! ✌
