If I remember well the IR sensor for the door is hidden under the black plastic line on the right speaker. Somehow in the middle. I think you can locate it by using a camera (you will see some light). Maybe you just need to clean this plastic line (you have to unmount the panel).
In the Service Manual (avail on this site to Silver and Gold Members) there are two mentions of ‘fixes’ for problems with door sensitivity. One involves changing a single resistor, and the other changing the IR transmitter diodes. Sneak preview of the latter below: