Check the little drain hole underneath the recessed fill cap, they have a nasty habit of plugging off and sending
rain/wash water into the tank, a sod to fix.
The filters very clean, the one on my EV was so plugged up the fuel was unable to get to the injectors, it would run for a while then just bog down I back flushed it at the KOA in Denver
then again when I got back to BC, the photos show the BC flush, I bet there was 5 times as much came out the first time.


This is all caused by the moat drain plugging off to sent water into the tank.