This is a workaround for the lack of a dashcam notification.
I moved the dashcam icon (not sentry) down to the bottom toolbar so it is visible. If the dashcam has a problem, there will be a small red 'X' where there is usually a small red dot. If you can remember to notice this regularly, you can fix it by reformatting the drive. I use in-car formatting, and it only takes a second or two. One time recently, I had to remove the drive and retry a few times before it finally worked, but I think that's something with a recent bug. Since then, it has been crashing every few days, but I'm able to reformat without removing the drive.
Please do not suggest I get a new drive. And if you suggest I use the official Tesla-branded thumbdrive, I will immediately add you to my ignore list.