The control wheels on my Canon 5D IV are not working properly anymore. It is 5 years old and I think that they have just gummed up with sweat and gunk. They still function but are not smooth and you often have to try several times to get the wheel movement to actually do anything. It has got much worse here in Sri Lanka where (of course) your hands are always sweaty. When I get home I plan to send it to Peter the camera repairer in Brisbane (if he hasn't retired yet).
Has anyone else experienced similar problems?