Hey, I'd love to have provided more info in case it helps anyone else out in the future, but now before you replied what I did was I just redid my Launchbox implementation -- so I delted all the games, and set them up using FS UAE UUID again. It works now, so I can no longer figure out exactly what caused my issue. Weird though, because I had treated all games the same, and I couldn't find any common ground between the ones that weren't working and the ones that were (vast majority were working)
I'm guessing you're right and there was some sort of problem with my Launchbox settings, and if I had to guess it probably had something to do with the fact that I didn't complete the setup of the FS UAE UUID on the first pass. I went back and did that after you helped me with it, and I might have overlooked something that was hard for me to detect in the process. But just starting fresh seems to have worked. Exciting