What you see pressing F11 is the refresh speed, 100% means it's matching the game's original, so it's supposed to stay at 100%.
And frame_delay doesn't create frames it's 'splitting' a single one (the last remaining undesired one, that's not what it actually does but the explanation is longer)
I've seen several users mistake frame_delay for RetroArch's run-ahead, but they're not the same thing at all, also people who've had experiences with other mame builds or RA generally modify several settings in Groovy assuming they work similarily, like we've seen in the case of the sync options...but nope they often don't ^^
Saying this though, I'm not sure what's going on for you, hopefully Calamity will have a look since you've attached a log. I'd suggest you attach your mame.ini as well.