So this problem is isolated with Firefox as it doesn't happen with Edge or VLC on this pc. If I have Twitch or Youtube, probably any other audio or video playing, open when I turn the monitor off the audio will no longer go through properly when it is turned back on. The video is still playing fine but the audio isn't going through properly. Refreshing the page fixes the issue. I have made sure to disable all other audio outputs and defaulted the current HDMI output. Audio playback works fine on every other application that I have tried. Running Windows 11.