Ok, so I have been lurking in this thread on and off recently. I don't have a straight up solution to offer, but maybe my story can help others shed some light on their issues and maybe even fix things.
I received two iPhone 7 Plus's (Verizon) for my son and I on Sept 16th. On Thursday, Sept 22nd my phone started getting the dreaded 'no service' in the afternoon. I spent about an hour with Verizon support and he had my cycle through some other sim cards I had (4 in total), but not one of them worked. He said it was probably a hardware issue because it wasn't recognizing the SIM card and I should exchange the phone before the 30th (14 day return policy). I have a ton of photos so I wasn't looking forward to it, but the one last thing to try was a complete reset. I'd already done a network reset and that did not help. This was before I started hearing about Verizon's HD Voice service possibly having a part in this, but more on that in a minute. So, I did a factory reset and restored my phone using a backup I did via iTunes that same day. When everything came back, STILL no service. I did a network reset just to see, and somehow my service magically came BACK to life.
I use Waze religiously and had already seen a lot of dropped GPS signals and even after I got my service back, the GPS would drop 10 times during my 40 min. commute to work. Very frustrating but at least I was getting decent service most of the time.
Fast forward to last Sunday morning (Sept 25th). My son came to me and said now he was getting no service on his iPhone 7 Plus! So I go through the same basic steps as I did with mine but still nothing - NO SERVICE. By now I had seen some of the comments about the HD Voice service.
So to try to wrap this story up, I removed it from both phones on my Verizon acct. and set LTE to data only. Since I did this I have used Waze a ton without any dropped GPS or loss of service. I did a factory reset of his phone and a bunch of restarts and network resets and I was finally able to restore his service as well (it was seriously painful).
I have no idea how long this will last, but I am really hoping someone (Apple / Verizon) can give some hard facts and a solution to this. I ordered two new SIM cards from Verizon that came today, but I have decided not to switch to them until I know there is a solution to this problem.
I'm probably leaving some details out but this post is way too long already. If you are having similar issues, I would recommend temporarily removing the HD Voice service through your Verizon acct. page (instructions are earlier in this thread) and setting your LTE to 'data only' for the time being. The earlier post said to add HD Voice back, but I'm not risking it right now.
I haven't noticed any major problems with voice or data, but I don't make many long calls either. The good thing is Waze seems to work fine now and I seem to have the same LTE signal strength that I have always had. Of course, this could all change tomorrow. If it does I will post. Thanks!