Extension is keeping my monitor awake

I have made some use of the Volume Master extension Vivaldi (7.0.3495.18) on Windows 11. I've noticed a few times that I had trouble with my monitor not turning off when I expect it to, and it usually resolved after closing what I thought was the "offending" tab (usually Youtube). After the latest incident, I realized that it was actually the extension causing the issue.

When the extension gets used, the Youtube icon changes to the Cast icon. So far as I understand it, it's because the extension is "casting" the audio from Youtube to the browser, so that it can change the volume. My problem is then because the extension is casting (even if the video is paused/done/etc) it prevents the screen from sleeping.

Does anyone here know of any possible solutions? Whether that be a different extension/feature; another forum to ask this question; a way to remove the permissions from to extension that let it keep the monitor awake?

Thanks in advanced!