I would guess the best option would be to contact the company you bought the Q9 from and get a replacement (that'll take time I imagine) or contact GPD directly to see if they can help. The problem right now is I think the Chinese new years is starting/started so you won't get much help for a few weeks.
Otherwise, you could try a few different things:
a) Factory Reset: Go to Settings > Backup & reset > Factory data reset
b) Reformat: Settings > Storage > NAND Flash > Erase SD card
c) Reflash firmware: Either using the official firmware in the sticky here
or install LegacyROM which is a clean ROM (no pre-installed apps) here
. There is a flashing guide in the LegacyROM thread.