Jaycee2017

We’ve been traveling Nevada & Utah in the upper elevations. Overnighted in Ogden, UT (ele 4300ft). My potable H2O is 1/3rd full and has been that throughout this trip. At all rv parks I’ve used city H2O hookups, no problem. Yesterday my wife noticed water discharging from potable water overflow. Turning off city water connection, 5mins later overflow ceased, checked tank capacity is now full. I’ll drain before to 1/3rd (preferred) before leaving park. Any thoughts as to why this happened. I’m using all correct outside attachments that I bought when I purchased this trailer. Thanks in advance.