@leetripper and
@nfsllow, thanks for that information fellas! So it seems there could be certain stock ROM firmware that could be outdated or incompatible with the custom ROM setup on LineageOS (and I'm guessing other Payton custom ROMs that use a similar device/vendor tree setup too) and the proper solution is to indeed try different stock ROM and see if that device firmware works better.
@Knuxyl I recommend seeing what they wrote and to try that if you are still having issues with LTE.
nfsllow, I from what others have told me? Apparently that issue isn't isolated to LineageOS for payton as they recommend trying other apps. You can maybe try Magisk with SafetyNet mods to see if that might somehow fix it, but it doesn't sound like it would unless that app is maybe checking for unlocked bootloader or something too?
They did say to try mparivahan or digitlocker apps. Those might also require Magisk and SafetNet mods to work though