Sounds like its broke from inside the barring that makes it move
Some will say if you really like the faucet fix it you will have to take it all apart
Or just replace it.
Shut the water off under the sink. remove the set screw holding the level on and lift off the handle. Unscrew the valve stem. Look it over and inside the housing for any trash inside. It's best to just replace the whole valve stem. Just take it to any plumbing supply or even HD or Lowes and match it it and replace it.
Remove the parts from the top down, disconnect the hose from the pull out spray and pull out the hose, Then remove the hub assembly. See if you can identify the brand & model for sure to locate the proper o-rings and hub assembly parts.
I have had one of these apart, let's say a cheap brand that was all plastic with two "O" rings to seperate the inside from the outside and there was what looked like battery corrosion that stuck the two plastics together. I clean it up and re-installed it and it worked fine for two weaks. Repaced it with a brand name unit.