Playback Volume Marker?

I was working on a project when something strange happened. Now there’s a marker in my playback that seems to limit the volume. No matter how many times I try to set it back to 100%, it keeps lowering automatically. Everything is also showing weird negative numbers for volume levels.

The playback volume was working just fine before this and was set exactly where I needed it. This issue affects all of my devices, but the volume on YouTube and Spotify still works perfectly.

Has anyone else run into this or know what might be causing it?