I just changed the bathtub handles, stem or cartridge(the part that turns), and the plastic cap and spring. It doesnt leak anymore but now I have a problem with water flow

When I turn the new handle past halfway the water ALMOST turns back off.

so as I turn the handle to halfway its at its heaviest flow of water and if I keep turning the water slows down like im turning it off but to turn it off I have to turn it back to the left.

It does this on both sides. Off is completely off. All the way to the right is minimal water flow and half turn is heaviest flow.

I also dont think its pushing as much water out as it use too.

Im not sure why its doing so so anyone have ideas? is it the new cartridges? do they not let enough water through?

Could I put in the old ones back? im not sure if it was these that leaked or just the spring and plastic cap(stem?) that leaked.