Audi A1 Knocking noise on/off accelerator

Hello,
I have a 2011 Audi A1 with 160K miles. It is front wheel drive.
I'm hoping someone might be able to give me some clues as to what my knocking noise is, as the mechanics have performed multiple fixes which haven't worked.

The knocking noise is coming from what sounds like the front passenger side. In first gear, if bump the accelerator I'll hear it on the forwards and backwards rocking of the car. It can occur in 2nd and occasionally 3rd gear.

The mechanics have first replaced the CV joint, as they said it was deteriorated anyway and could be the source. This did not solve the problem.
I then decided to take it to an Audi 'specialist' who replaced the gearbox and exhaust mounts, which appeared to be a guess as he didn't listen to the noise.
This has not solved the problem either.
I went back to the original local garage; but they said they could not find the source of the noise and everything looked fine.

Someone with some experience may be able to give me some advice on components to replace?

Thanks