UPDATE: the primary issue has been resolved in later post below. Thanks!
Would it be possible to save a backup of the current s/u, restore a previous backup to copy that key I refreshed and then reload this current backup to paste the key to get that S0 back the way it was? Is that even my issue?
Amazing news! It was indeed something simple. As embarrassed as I am to admit just how simple it was, I feel compelled to do so since some may be reading this in an attempt to help me out (and big shout out to those who are)
On a whim, I decided to go put the PoE adapter back in the location it was in connected to the network cable it was previously plugged into. Bam! Things fired right up!
I tried to delete this thread as a whole to prevent anyone from wasting time reading that novel when it’s already been resolved but the system will not allow me to, sadly. I added an edit to the very beginning of the OP to save people the effort since that’s the best that I can do.
Now, to figure out this deadbolt issue and see if I can address that Add-on issue as well.