Button rear cover without function

Hello, after my Phaeton sometimes starts self-healing (e.g. switch of electric sun protection on the sliding roof suddenly goes again after months), I have been beating around with a new little something for weeks now: My wife complained repeatedly that divh the rear cover did not always open electrically. This error was simply not reproducible with me. So I made life difficult for the lid and during an opening process repeatedly actuated the button on the inside of the lid. Everything was fine. I thought… since then the button on the inside but no longer works. Now I certainly will not have caused the typical cable break. The trunk can now only be closed via the VW logo. Continue to open via remote control, driver door and VW logo without any problems. Just not the closing. Now I also determined that the luggage room lighting sporadically doesn’t concern, so that the button also has no lighting and it also does not get bright in the rear when opening the rear doors. This does not happen after a short time, but no matter of having a problem, but not having to read it again.