Have you checked each folder and see how many files are there?
When you record in TS format, the TS file is written concurrently with the files in the folder. When recording has finished, the folder should be deleted. We do sometimes see a few files left in each folder, due to unknown cause. I have been trying to figure that out for a long time but with no luck. If it leaves more than a few files in each folder, it may be more than what I have been seeing.