Video files stopped initiating when double-clicked, if VLC is already running

[PhatTony]

I found a post about this from May 2018, but windows specific. None of the proposed solutions had any affect.

I'm running VLC 3.0.8 on a MAC desktop. It used to be that if I double-clicked on an .mp4 file (or any video file) it would automatically open in VLC. Now, however, if a video is already running, or was opened, the new video will not load. I need to close VLC, then if I double-click on the video file it will load. This is incredibly annoying, having to close VLC every time I want to play a new video file.

What is the solution?