A couple of months ago my neighbor called me over and she had no water pressure and a couple of days later no water at all. I took the water inlet out of the unit and tore it apart and there was a backflow/water pressure regulater built in and was plugged and also had broken parts in it. A trip to camping world and $45 later she was back in business. She now has lots of water pressure again.
Now this was on a motorhome but I am sure most RV's are similar.
You may want to see if yours has a backflow valve in it or a pressure reducer built in. She bought something similar to this.
https://www.campingworld.com/pressur...try-wall-mount