I have had an intermittent problem with my camera cover ever since I replaced a housing. It recognizes opening but not always closing. The problem is that the black part of the black and white patch inside that moves when you open and close the cover is not black enough. Refreshing it with a Sharpie from time to time helps but it is a lousy workaround. Eventually I made it a bit better with a small piece of a black sticker but still not 100% perfect.

The magnetic sensor for the SD card mounting is polarity-sensitive. If waving a magnet over it does nothing, try turning the magnet around and try again. Also, you did not specify in any of your threads what ls /dev/mmcblk* prints.