I'm now having issues with band 12/17 since the update!! No calls go thru or come in and texting has the same issue!!
I tried selecting band 17, and that didn't work.
Actually I've changed my band to [C] which is "LTE/WCDMA/GSM Auto" and it's worked flawlessly so far.
I've also disabled VoLTE which has prevented the duplicate SMS messages from happening so far as well.
If this lasts for at least a week without losing connection then I'll probably just keep this as a solution for now and think about a new carrier after my contract is up.
select  Band Selection
select [C] at the bottom, confirm selection on next screen