I was shooting with this lens on an R7 body, with adapter. No problems until it stopped focusing with Autofocus entirely. I switched to manual focus with no luck. I tried changing to a 5D III body with similar results. Only able to focus with either ...
Since I haven't moved the switches in years, I doubt that flicking them ten times would wear out the switches. At least I would hope that Canon would use durable components, LOL.