Thank you for your responses. I am using pucks and I alternate liquid every few applications.

I took a sample to the pool supply store to get it tested (to confirm that my test kit was accurate). They confirmed that the readings were correct - Cl is about 10ppm and CYA is about 115ppm (down from 150-ish).

I am going to stop adjusting the chemistry and leave it as-is (as was recommended above). They CYA will eventually come back down to normal levels.

I think that I need to go away from using the pucks as often as we have been using...