i have the exact same issues with everyone else on here. i had Rogers send out my S7 for repair ,they replaced PBA -other -BGA FAILURE and minor component parts so far everything running smooth now no drop calls and LTE problem.
I recommend everyone with the same issues send your device in for a repair.
Ya I think all these people who think they found a "fix" have really just not given it enough time to see the symptoms again. I got a new phone and it seemed fine for a week, but then the problems returned. I also had a Rogers tech disable the VoLTE signal for my account and it fixed it for a week, but again the problems returned. I switched my MMS proxy and still the problem persists.
Give it time, the problem will return. Give it more time, these guys will eventually fix the problem. Give it even more time, your contract will end and we can all finally switch carriers.
I went on SamMobile to find another carrier's rom. I installed and it's been a week and no drop calls or anything like that. The only thing that bugs me is that they replaced "LTE" with "4G". You may be thinking that's not LTE blah blah blah. I tested the speed and it's LTE indeed. From time to time i'd see 4G+ too lol.
I'll see how things go for now. To be honest, I hate my phone showing "4G" instead of "LTE" despite it really is LTE.