I will not be able to fix VoLTE - I am afraid. For disabled SIMs: I would suggest to try to activate the SIMs with the original/stock motorola ROM and see if this helps to provision them.

ATT started disabling any SIM cards on banned phones that do not have VoLTE at the first of the year. I knew about this but was caught off guard and the SIM was disabled in 18.1. I flashed back to stock and SIM did not work. I had to ask ATT to re-activate it. Then it worked on stock. I flashed 14.1 and the SIM worked. Then I flashed 18.1 again and SIM was once again disabled requiring 2nd call to ATT.
Verizon SIM also found to not work on 18.1. Googled and they started dropping CDMA phones at the first of the year as well. LTE ran for 30 seconds and dropped down to 3G. It was not disabled. I flashed back to stock and SIM worked with VoLTE. I flashed 14.1 and SIM worked with VoLTE. I flashed 18.1 and, to my surprise, SIM worked but no VoLTE as expected. I have left it well enough alone now it works but expect they will eventually find me and it will stop working.
No VoLTE will be a problem.
Can we get it to pass Saftey net on Magisk?
I flashed the update and I had the same problem as
@moviefirst and it was unable to unlock my phone as PIN was unrecognized. Don't want to reformat data and hoping you can post a fixed update. I could see that the Verizon SIM was still working, that's a plus.