Thought this. And could be, but I’ve ruled it out for now.
Changed my 12v in June 2020 when I noticed the car wouldn’t start on some occasions. “Shift lever into P” error message.
No clock issues back then, none whatsoever.
I notice time keeping issues nowadays, even after a trickle charge back to full.
Never say never but I’m not convinced it’s the 12v at this stage.