Oh, the contactor problems rang a bell. I was trying to check the health of my 12 V battery with the HV battery safety plug pulled (which disables the HV contactor). I had turned the car off in the Safety menu & left the passenger door open. The 12 V battery voltage fell to 12.2 V, which isn't good, and when I plugged the HV safety plug back in, I could not get the contactor to pull in. The 12 V battery should have pulled it in. The battery voltage fell below 12V. I had to put a battery charger on the 12V battery to get the contactor to pull in and get the vehicle back to life. Once the HV battery started charging the 12 V battery again, the vehicle seemed perfectly OK.
So, could your 12V battery be dying? That might also explain some of the other anomalies you're experiencing. I had a Prius prior to my MX, and it too relied upon a 12V battery to boot up the car & get it running. If that 12V battery became bad, various "mysterious" malfunctions would start to occur ultimately leading to the car just dying & refusing to wake up. I wonder if Teslas behave somewhat the same way.