I can say for certain that my snes multi chip would not sync when the ossc was set to a profile I created for my genesis for instance. Make sure you’re starting from default settings for the snes. I also have random no syncs on my snes that I haven’t pinpointed the cause of yet. I jiggle the everdrive, disconnect and reconnect the scart cable a couple times and it eventually works again. My best guess is its one or the other is a dirty connection, but I’ve been too lazy to clean either properly since it is intermittent and resolved itself quickly.