LTE connectivity problems after ios updates
I'm new to the forum but have read many threads through the years that have helped me a lot when having phone problems. Right now, though, I'm stumped with a problem I'm having and thought I'd ask for help.
I have an iphone SE that I bought a little less than a year ago and put on the Page Plus account I have had for at least 5 years. I've had several iphones, but I've never been much of an "updater" with ios because I've always heard of people's phones messing up afterward. I thought it would be good to keep this one up to date. Right now I'm thinking that wasn't a good idea.
I'm pretty sure my troubles began when I updated to ios 11 back in November. It started with intermittent loss of LTE. As time has gone by it has gotten progressively worse, to the point now that I rarely have LTE that works. (it often shows LTE, but doesn't work). Typically it will drop down to 1x and then go to 3g. Sometimes 3g works and sometimes it doesn't.
I have tried everything I can find, short of a complete reset of my phone. I have done the following:
"Reset Network Settings"
"Reset All Settings"
"Erase All Settings" and the restored from a backup
Spoken with PPlus on chat and removed and replaced the SIM several times as they did whatever.
One interesting note: i have an iphone 5s and an iphone 6plus on my Page Plus account and they have the same problem, except that I have been able to reset the APN profile on those two, and that has helped for a while but the problem returns. I cannot do it on my SE, though, because of an error message saying I can only install "one profile at a time" and I can't access any setting that allows me to delete the old profile.
I mentioned the APN profile problem to the PPlus rep, and because I could not access the settings on my iphone that allow me to make changes, was told that "this is what my instructions say to do, I don't have any other information" (something like that, anyway).
I have not tried putting my SIM into another phone, but it seems unlikely that would be the problem since I have two other phones acting the same way. I do plan to test it later today though just to see.
One other thing. I recently traveled outside of my area, and I had normal LTE service for a while, maybe and hour or so, before I started having trouble again.
I apologize for the length of this post, but I wanted to be thorough. Thanks in advance for any assistance.