Prime beeps when put in park

I've read a lot of beeping posts but none quite match what's happening.

This is my son's 2020 Prime. He is in California and I'm on the east coast so I'm trying to figure this out without actually being there.

The issue is that recently, when he comes home and puts the car in park, the car beeps at him. Just one beep. Nothing on the screen. No indicator lights lit. But he says it sounds like the car is trying to tell him something.

I've seen people say that if the battery is starting to die, some strange things will happen, like random beeping. Because of some things below, I bought a little dongle that is supposed measure the battery voltage. Attached is a picture showing that it claims the 12 volt is delivering 12 volts after sitting over night .

Full disclosure:

• Maybe 18 months ago when my son was away, I let the battery run down bc I did not know about the issues this car's battery has. I trickle charged it and it has worked fine ever since.
• In his current location, he rarely gets to charge the traction battery.
• Early this year, he was in an accident and the right front fender got pretty smashed up, the tire twisted around. But after the repairs it ran fine up until recently.
• The car was shipped to CA, not driven that far.

Thoughts?

 

Hm. Crickets