I replaced the mixet cartridge in my shower in my house that was built in mid to late 1980s. However when I turn the outer volume knob either clockwise or counterclockwise to turn on the water, or to shut it off, it grabs the temperature knob at the same time and spins it. So the only way to really turn the water on and off is to hold the temperature knob with one hand while I’m turning the volume knob. What am I doing wrong?