What does Secure Check Fail Radio mean?

[akumm44]

A few days ago, I got an update for my Samsung Note 5 (SM-N920V) which is currently running Nougat, from Verizon Software Upgrade Assistant. I tried to run the update from my laptop and the update failed. I tried to run the repair and the repair failed. The error my phone was showing was "Secure Check Fail (Radio)." My device was bricked. I tried using Kies and SmartSwitch, but still get Secure Check Fail (Radio). I tried using ODIN, but still the error would show "Secure Check Fail (Radio)" at the end of the download. After using ODIN to download just the PIT file, it's working again, but I have in the settings "Service Provider: KT twophone service" and only have CDMA option for mobile networks (no APN settings). I was previously using this on a GSM network (not one of the big names).

Does anyone know what the "Secure Check Fail (Radio)" means?
Or how to get GSM access back on the phone?

(I am not trying to root the phone, I just want the stock Verizon version back!!)