Still the question remains. If you simply pull out the USB-stick, the "dirty bit" is always set due to the fact it was removed incorrectly.
The previous FYT Settings app had the option under Storage, to remove a USB mass storage device safely.
That is currently missing.
It is one of the big errors that cause faulty flashes of firmware. In 95% of the cases where you see a wrong flash in the forum or the Telegram channels, it is because the usb stick has some corruptions.