Based on the reported behavior, the most likely issue is that the lens focus drive is occasionally failing to start or is slipping when only a very small focus adjustment is needed. That would explain the motor-like winding sound and why AF works again after switching out of AF and back.

A simple test is to gently nudge the focus ring when it gets stuck. If autofocus immediately resumes, that strongly suggests the focus mechanism or motor is struggling to get moving rather than a camera-body setting problem.

So yes, it may indicate wear or a developing fault in the lens autofocus mechanism, but from the information here it’s not possible to say exactly which internal part is responsible. Since it’s a used lens, monitor whether the problem becomes more frequent. If the nudge test reproduces the fix, the lens likely needs inspection/service rather than the camera body.