0924 on the unit here shows the same issues in parking mode in FAT32 and H264 using the Integral 256GB U3 card as the Sandisk 400GB card did once full, ie it writes out truncated parking mode files.
It was fine until the card filled so it's something to do with looping, maybe a buffer size somewhere.
I'm not sure what spec the A129 Pro is memory wise - I've seen other Novatek NT96685T based systems with up to 512MB RAM but more for telematics than just dashcam use so they have a lot more going on sending that up to the cloud constantly.
Thinking out loud about it if the camera buffers 45 seconds to RAM so roughly 100MB per 2 channels and it's most likely using what would have previously been available for file cache write buffers potentially for that, so without automatic parking mode it may have no issues as it's happily throwing stuff down to storage with an extra 100MB RAM available for caching purposes to cope better with slower cards or transient slow writes.
Heck caching might even be turned off completely so it's entirely card dependant - only
@viofo could answer that.
Something to test for anyway and maybe why people not using pre-buffered mode aren't seeing issues.
I've been over to York today so used the Integral one way to fill it and then swapped back to the Lexar 64GB exFAT card to see how it exFAT testing goes.
I've left the Lexar in the car and will try to fill it tomorrow (won't be hard at 64GB) to see how things are looking on the exFAT card - it never beeped on the way home in an hour tonight with the 64GB exFAT card.
Now I don't know if this is entirely coincidental but the camera has now done the double beep (card error?) at exactly the same spot in my drive twice now on the Integral card. Literally the same spot within meters, it's early in the drive too. 4 minutes in fact from engine on as you can see from the below.
The rear file is larger just as it errors (135.9MB vs ~121MB) and then the small file before it returns to normal before carrying on. No more issues in another hour of driving after that. The card wasn't full at that point but is now.