Had this same issue today, which is why I’m here of course.
4hr print, which I had already printed twice before with no issues, and it stops at roughly 70%.
Now, I’ve seen people blaming this and that, and claiming fixes are this or that, but the only consistent thing I’ve read is the prints are about 3/4ths complete when this occurs. That hardly seems like it’s a random issue of power fluctuations or SD cards.
My card is at 10g. Stock card. That’s not remotely full. The printer was bought in November. And if you think the cards are all hitting their read/write tolerances at this point, that would be pretty far out there.
This sounds like a firmware issue that has not been solved. And I’ve yet to see an official response from Bambu about it, but I’ve only started looking into this as it and plan to contact them as my equipment is definitely still within warranty.