I've searched but can see anyone with same issue.

When turning volume up using volume knob on headunit the volume will revert down to a low level, usually 0/zero. I can get it to function normally if I apply a sideways pressure to the knob. Sometimes a few firm simultaneous presses and turns gets it to behave but this will usually be short lived. I've kind of learned to live with this little idiosyncratic detail but I think Ill get it sorted properly for once. No controls on steeringvwheel

So, anyone have this issue and found a fix. Its not the same as the max or zero volume issue people have encountered, this one always drops the volume. I'm tempted to open up tbe head unit and give whatever lives behind that knob a good dose of contact cleaner but not sure if I'll just be wasting my time.