My car is quite a bit older than yours but same model. 2018 Model 3 LR RWD. Was in the middle of driving cross country on a house move. 18 miles from my stop for the night, I heard the pop (in motion it almost feels a bit like someone rear ended you) followed by the sudden alarms to pull over immediately as you are about to lose power.
Now, this was past 11pm on a Friday night. Roadside (had about a week left on it actually) got back to my initial message through app in about 30 min. They were trying to get a tow to me. Took about 3.5 hours (this was in Oklahoma City). They wanted to tow it to service center to sit in a lot for Saturday and Sunday since service didn't open until Monday. My driver side window rolled down and would not go up. I had a lot of belongings in car due to move, so I had them tow to the wrecker's yard due to it being locked/staffed 24/7 and cameras on. They did. Got some adhesive plastic up on driver door to protect from elements (good thing too..hard rain Sunday night).
I met tow driver at Tesla service this morning (This tow I had to pay out of pocket as roadside covered "a tow" not multiple). They seemed convinced it was 12v. I told them it was only 2-3 weeks old (I had it changed before trip to avoid being broken down). First service tech gets in car. Pulls up the errors. Says "it's more than 12volt". Helped them push it into service bay to lift. Super hard to push...had me thinking rear motor was bad. They offered me a loaner...so I took it and went back to hotel I'm paying for to figure this out. Contacted them later. Yup. Rear unit drive/Inverter and the pyrotechnic fuse (likely the pop I heard/felt). They claim 9/8 on tentative parts ETA. 1-2 days to replace after they come in.
So I'll finish my move in a rental, fly back to OKC to pick up car when it's ready and drive it back...hoping and praying it doesn't happen again. Confidence in Tesla trouble free driving is a bit shattered for me now.