Sony TV / Vizio Sound bar Issue? Update

Good afternoon all, I'm hoping someone may have some insight on this that I haven't tried or researched yet. Sorry for the long post but I'm at my wit's end.

I have a Sony X930E TV and a Vizio SB3651-F6 sound bar / audio system. The TV has been working great since 2018 and the sound bar has been connected to it via ARC since 2019 and has had zero issues, other than the occasional instance of not automatically switching over to external speakers when turning the TV on.

Until about a week ago... Nothing has been changed on my end, no TV update, no change in HDMI port, cable, no power surges, etc.. but now the TV doesn't recognize that there's an audio system there. The TV audio / speakers work normally. It's acting strange. I'll go into detail of what I'm seeing and what I've done to troubleshoot so far:

The TV used to automatically switch to external speakers (audio system) once it detected it, which usually took me hitting the volume buttons on the remote (sound bar was being controlled by my DISH remote). When it would switch over, the HDMI-ARC lights on the sound bar would blink. Now it doesn't switch over by doing that, and when manually switching to external speakers, the sound bar HDMI-ARC lights don't blink. I can select the HDMI-ARC input on the sound bar with my sound bar remote, and the lights blink but nothing happens, it's like it's not even connected to the TV.

Also, to get a bit granular, on the quick drop down "Actions" menu on the TV there's the "Select Speakers" option, where I can manually select TV Speakers or Audio System. Before, when toggling that selection of TV Speakers or Audio system, that menu would remain open, and I could toggle back and forth. When selecting one of the options, the 'button' icon would turn blue when clicked on, then white with a dot in the middle showing which option was currently in use. Now, when I have that menu open and I select the other option (than what's currently selected) both dots turn blue (as if they are selected at the same time) and the menu closes. Not sure if this reveals anything but it's an odd behavior change that I noted.

I've checked for TV updates and it's up to date.

Cleared the cache in the ExternalInputService system app. No Change.

Factory reset the audio system. No change.

Unplugged power to the audio system for several minutes / hours and plugged it back in. No change.

Soft reset the TV several times, both with the audio system plugged into ARC, with it unplugged, etc.. No change.

Tried several different HDMI cables. No Change.

Switched the sound bar to a different HDMI port on the TV. No Change. I don't have an optical cable to try that, however I want to use the ARC port to enjoy the features that yields over optical.

Unplugged all HDMI cables from the TV except for the sound bar / HDMI ARC port. No Change.

Switched my Dish receiver HDMI cable to the ARC port on the TV and it worked with no issues, transmitting the picture and sound through the TV speakers. So the ARC port works.

Moved the sound bar to my bed room TV - Hisense R6, tried different HDMI cables, including the one that was being used for the sound bar, and it worked perfectly through that TV's ARC port.

Plugged my Dish receiver HDMI cable into the HDMI input on sound bar, then the HDMI ARC output from sound bar into the ARC port on my TV, and got no sound through the audio system OR the TV speakers. Picture worked fine though.

Sony calls the CEC on this TV 'Bravia Sync", and I've gone through everything I can to enable and recognize devices through that, but I don't expect it to since the sound bar is not a Sony brand device, and it's not listed on Sony's approved devices list for the TV. That said, I did go through the steps of the TV sending an "enable" signal to all HDMI devices and nothing returns as recognized. But they didn't before.

I've done all the steps in Sony's troubleshooting / help resources found on the TV itself and through internet search and no joy.

I've done everything I can think of except for hard / factory resetting the TV, which I've admittedly been trying to avoid due to all of the settings, apps, and logins I would have to bring back up to speed once that's done.

Does anyone have any ideas of what could be causing this and what a possible solution may be? As stated, everything was working perfectly until about a week ago, when we turned the TV on and the audio just wouldn't switch over.

I did order some new HDMI 2.1 cables just for the sake of upgrading them all with the times, but my troubleshooting has proven that it's not the HDMI cable.