The check valve on your water pump is not seating properly, allowing city water to fill the fresh water tank. One thing to try:
1) Turn off city water at the source;
2) Turn on your water pump and open-and-close various faucets in your camper allowing the water pump to cycle on and off;
3) Turn off water pump, open a faucet and relieve water pressure;
4) Turn city water back on.
Never turn on your water pump when hooked up to a city water source.
2014 Micro Lite 19fd
2015 F-150 5.0L V8 XLT Crew Cab, 4x4, Tow Package, 36 gal tank, 3.55 locker, 1891 payload, Integrated Brake Controller, Roadmaster Active Suspension
Wooden Spoon Survivor