Who I have the same questioned this topic

I would surmise that, given the update is a software update to (perhaps) control hardware and other software (apps/OS) that it is software related.  If an FDR does not solve the issue, and given you cannot officially rollback an update, and also that you are out of warranty, you might have to try other methods not mentioned here.  If Verizon's SUA app does not or cannot recover the update from error, then other avenues would need to be sought out, such as repair, replacement, new phone, or other software options.