Canon 500mm f4 mk1 owners , with R camera...

Feb 27, 2021
33
11
hello,
i've a Canon 500mm f4 mk1 and having some AF issue,
AF is perfect till it is not and become heratic for some periode and all of a sudden AF is back for no reason as i do not do any change.
It's just like if the lens need some "rest"...(???)
the lens seems working great, the camera R5 too, it's just the combo .
So i would like to know if some owners of the 500mm f4 mk1 experiment some issue , or not, and may be , what's your best setting with this lens on the R5 or R6?
thank you ;)