My current shower diverter is not working properly as a stream of water continues out of the tub spout when the diverter is pulled out for the shower (it's a three piece waltec set up as pictured below) I purchased a new diverter and had no issue putting it in, however the knob doesn't stay pulled out and even if I hold it out without letting go, only a small amount of water goes to the shower head. It's worse than the old one which at least partially worked. I thought maybe I bought a dud but I took a look at another one from a different brand and it also doesn't stay pulled out. This leaves me wondering if I'm missing something in the installation process??
Old and new parts:
Old and new parts: