Why do I lose a significant amount of volume on Plex Media Player?

Yes, the speakers I have has its own volume knob that I have at 100% and I control the volume using the Windows volume control. I actually found one of your other posts here and this seemed to bring the volume level to an acceptable level although still not as powerful as if I played the files directly in VLC:

But thanks as it is a much greater improvement. Now the volume on the Roku app. How can we fix that?