I had a 2011 version RNS-E retrofitted into my Mk2 TT a while ago, the installer coded and wired up the Aux port and it was working fine.

I just had an external amp added to power the new front channel speakers. The installer spliced the front L/R line signal into the factory amp and also the front speaker output. When everything put back together, the Aux port is not working anymore. We've tried to check all wiring into the RNS-E and it all seem fine, nothing has changed in there.

Have someone had similar issue or know where to actually start investigating? I can still see the AUX input source in the rns-e but could disconnecting the factory amp cause the rns-e to reset?

Thanks!