All the music files had strings of characters added to their file name. All of them. In every folder and subfolder. The names were long, VLC displayed them in marquee.
In that player those changed names didn’t show, but un any other player and file manager they did. Which I found out when sicmu started having playback issues and I opened VLC.
That was perhaps the 2nd or 3rd version of it posted on FDroid. I used to search for a folder player a lot and so tried the first version posted there, it was great until that update.