This is pretty common, and that A4 that you'd had? Whoever had it before just put in enough to show F and not actually fill the tank. Very common tactic for rentals, too. F is more of an indication that you've got a bunch of fuel rather than actually being full, and the marks are just a gauge of how much more you have to go. Not sure why they do it that way (I can see having E not be "running on fumes" for safety reasons, but F being held so long on everything is a little odd -- but very common).