Engine knock with an odd pattern + rough idle after new MAF (video included)

Well I’ve looked/listen to numerous videos and I can’t find anything that replicates the noise that my 1999 XK8 is producing

Video Link

The knock has a consistent wave pattern (comes-and-goes, versus knocking every rotation). Idk if it’s correlated, but this knock (and rough idle) came after replacing the MAF.

My troubleshooting process:
Lean codes (P0171 & P0174), but smooth idle and no knock → Seal all vacuum & exhaust leaks, new MAF, reset ECU → Drive Cycle → Rich codes (P0172 & P0175) → MAF error (P0101), Rich codes (P0172 & P0175), rough idle, engine pattern knock → reinstall old MAF, reset ECU → rough idle and knock are still present → clean and test MAF plug contact points (all good) → test idle without the MAF plugged in → same rough idle and knock

The car knows the MAF is being plugged in because it does temporarily correct the idle when I plug it in as the engine is running, but it quickly reverts back to the rough idle and knock shortly after.

Any other ideas?

No idea but it sounds not good to put it mildly☹️