OK. I understand now. But now I'm wondering why the bios files are even being listed.
(this is kinda bugging me, and I'm bound and determined to figure this out. Or have someone else tell us)
I believe Maximus Arcade (MA) get it's list (.lst file) from: executing mame64.exe -listxml, then comparing that with the roms folder to get the available games and their 'proper' names. So it
shouldn't 'show' the bios files on the list.
Maybe... (as a thought)
In MA Preferences, Options, MAME
...check "Disable unplayable roms.."
(I really don't know. Just reaching....)
What emulator are you using to run the MAME games? I assume mame64.
Is your mame64.exe compatible with (the same version as) your roms?
(not sure how much difference these would make for this issue)
If worse comes to worse and MA does not cooperate (though it should), I found another (multi-step) way of creating a mame.lst file of your games without having to go through and delete individual roms/bios/games... off the list.
(Run mame to generate an xml of your [working] games. Run [something like] LightSpeed to convert it to a 'special' MA-type txt file. Then run Game List Converter to convert that to a MA .lst file.)