I’ve been able to dial in consistent optimal timing settings for my model 1 Genesis without issue, but I recently got a model 2 Sega CD attached to a model 2 Sega Genesis, and with this setup, I have to readjust the sampling phase with each console use before playing. I had a similar (but not as bad of an) issue when I had a 32x hooked up to my model 1 Genesis, but I always figured the patch cable was causing some kind of funkiness with that setup, and just disconnected the 32x for the time being.
I’m using HD Retrovision YPbPr cables and haven’t been able to find an instance of needing to constantly change sampling phase between uses anywhere on these forums or elsewhere. Is this something anyone here is aware of and is there something I can do to mitigate the issue?
EDIT: All consoles are US, unmodded. HD Retrovision cables are going straight into OSSC input 2. OSSC is outputting to an HDMI splitter (which goes out to a Startech PEXHDCAP60L and an Acer monitor.) The issue persists simply from boot and is extremely obvious when booting to the Mega Everdrive menu (which I have mostly being doing.)