Help with Turbo Buttons

I know there are previous questions about this, but I can’t seem to get it running. Trying to play some shooters in MAME current and need some turbo to preserve these old hands.

I understand that the principle is to set an “active” turbo button, hold the button you want turbo on, then click the activate button… however, it just doesn’t seem to work. I’ve tried changing the set button to activate (although I would prefer L3) and I have switched between the single button toggle and hold options… neither seems to do anything.

Any tips on something I might have missed would be appreciated. Thanks.