Pull the faucet hose out enough to put clr down the shaft. Let it set for a few minutes then loosen the bottom nut under the counter that will give you enough space to rinse out the debris. Tighten back up and your problem should be resolved. I will use a product called break loose when assembling these (hundred+) and never have an issue with it . In my city the water ph is 8.5 so it doesn’t matter what type you get they will always have back water go into the cup and that will calcify making them difficult to operate. I hope that helps.