2020 Forester 3011DS bought new, NEVER took fresh water easily from the filler tube. I have not yet viewed the fill tube but it feels like there must be an antisiphon type curve upward that creates a pool of water in the hose. This necessitates a need for high pressure to overcome that pool. Once i get the water flowing into the tank i have less backflow until i approach a full tank. There is always a little backflow while filling. I am not certain i have ever achieved 100% full on fresh tank. Just yesterday i obtained a 3 foot extension tube for my filler device that i will be testing later today. Hopefully i can report good results later.