Hey,
I had the same problem and same material (Fuji x-h2s + CF Express type B av pro se 512gb), but when I read the files directly on the camera, the file was fully readable (no time / size limit). I assume the problem comes from the fact the files are not poured to the computer from a CF Express card reader.
I'm going to purchase a CF Express card reader and will come back to you if this works.
Roberto47 got a reaction from man-overboard in Fuji XH2s Stops video recording after 6min - max 4,29gb file