Sometimes I have PotPlayer running on a 2nd monitor and I can use the Play/Stop Key on my keyboard to control it, even when using other programs. Except VO, where nothing happens. Is there a setting I'm overlooking?

Windows 10, AZIO multimedia KB, backlit works fine on my end

Some multimedia keyboards will work as they send a "proper" media keystroke to the OS. Some wont, as they just send a key combo. It's usually the cheap crappy ones that wont work in my experience. One way to find out is to try bind a VO function to your mutlimedia keys. If it binds using the keyboard menu, it's not a real media keystroke being sent.

It's a Logitech G910. Not sure what you mean about binds using the keyboard menu. If I select an option (like Weapons Group 2) and hit the "Play" button it binds a Square symbol to it.
Mute and Volume work btw.

Yeah, which means it is not sending the true multimedia key to the OS, and the logitech software is doing the right thing.

If it is picked up by VO at all, it's not VO's fault but your keyboard. Not much guild can do about that. It is not like they can support every single device in the world, especially crappy ones.

Mute is sending key code 173, Volume is sending 174 and 175. Those work.

Play/Pause is 179. Not working.

Logitech Software is not running.

I hate Windows.