Sony 70-200 OSS f4 Lens Issues

[robk47]

I have a Sony 70-200 OSS f4 lens on my Sony a6000 and use it for shooting fast moving sports; hockey, football. The last few times I have been using it, the lens seems to be fine and then starts hunting losing focus. To get it back in the groove quickly, I have to turn the camera on and off.  I the camera set on C or AFF, as I vary it to try and counter this issue. Then I get the lens start to clatter and I have to turn the camera off and restart it. Is the lens at fault? Is the camera the culprit? What is suggested here?