CLP-260 Stuck Black Key

Picked up a used CLP-260. A black key is sticking. Took it apart and cleaned some gunk build up and changed out a spring. Worked fine with keyboard free but as soon as I reinstalled it, the key stuck worse than before. Taking a break before troubleshooting. I’m going to try swapping it with the same key at the high range and see if that helps. Wondering if it needs to be greased again.

Any thoughts?

Also, can you cheat and shift the felt down 3/8” to address loud up action rather than replacing the whole strip?

Thanks!