Fresh water fill

More clarification about my issue. When I am hooked up to city water I have good pressure and can fill my fresh tank, like it is supposed to work. After a while, I lose pressure and can not fill fresh tank through the wet bay. The only way I can fill the fresh tank is manually through a fill port in the tank. I have changed the fill valve, all in line screens and the whole house water filter in the wet bay, and took water pressure regulator off (pressure here seems to be very low). The only thing I noticed is the filter the dealer installed was in upside down. Waiting til morning to see what happens.