TLDR: if you have Xfinity, get the upgrade to the DB8 modem. It solved my issue.
Ok, update- so apparently it WAS some kind of network issue, brought about by the matter update that Hue pushed out which did not work. My network could see the bridge but was not allowing a connection to go through between the bridge and Apple. Hue told me to have Xfinity (my internet provider) check for network issues on their end; however, would not tell me what exactly to look for, so the network IT guys were unable to find a problem. They did tell me there is a new, updated, gateway available that they could send out to me which would get me faster speed. After searching for solutions, myself online, I came across a reddit post that said someone was able to fix their issue by replacing their existing Xfinity gateway with the newest version, the DB8 gateway. I contacted IT at Xfinity again and determined that they were in fact wanting to send me the DB8, so I said sure. I mean at this point; my next step was to go scorched earth on HomeKit anyway, so it was worth a shot.
The new gateway arrived and I installed it, and low and behold- the bridge now connects with HomeKit again! Yay1 The downside? I had to figure out how to split the bands apart (out of the box it combines the 2.4, 5 & 6 together into one signal). why you ask? Because the new gateway had a new SSID so nothing ELSE in my system recognized the network so EVERYTHING else in my HomeKit had to be removed and reinstalled. Exactly the scorched earth I was trying to avoid. On the plus side, hours later everything is reinstalled in HomeKit and running smoothly. Fingers crossed it stays that way!