My water shutoff valve broke, in the process of replacing my water shutoff valve I had to replace my pressure regulator valve because the local supplier didn’t have the fitting I needed. After replacing both the water pressure to the house will start off with decent pressure but drastically reduce if you keep the water on or are using multiple sources at the same time. I reinstalled the original pressure regulator valve and the problem stayed the same I also tried adjusting the pressure with no change to the pressure. Any ideas what might have happened?