C6 S6 Oil leak. Gaskets changed

Hello, I’m new to this forum. I purchased a used S6 a few months back. No issues for the first 30 days, then the leaks started. I had all of the gaskets changed, and the OSV changed as well. The leak stopped, but now I’m getting an oil burning smell and smoke from the passenger side of the motor. I took it back, and they told me it was the oil pan gasket (that was changed 1 month prior). I left with the car, and it was good the first night (local drive home). The next morning, I got on the highway, and the smell/smoking came back the exact same way. Returned to the shop, and now they’re telling me its coming from the head gasket. The owner told me, it is a known problem with these engines, that the headbolts need to be retorqued. Has anyone heard of this issue, or is there any advice you could offer?