This must the ignition advance version of the Schrödinger's cat thought experiment where observation changes the outcome!
Rather bizarrely, the distributors on mine and Jen's FF2000s (pintos) had both massively moved overnight at Silverstone one race weekend between Friday test and saturday quali first thing. Still a mystery. They ran fine all day, then the timing was out overnight. We can only think that someone moved them, but that's nonsense as who on earth would do that?
Sorry, not a very helpful comment from me. Other than, once done up dizzys don't move, so the problem must be in the internals. Or a problem of measurement. If it was me, I'd swap another dizzy in (assuming I had one I could swap out or borrow or had a spare) to try and narrow it down.