help with sticky keys?

https://reddit.com/link/1hlluzz/video/gn3nfc6hwu8e1/player

I'm new to typewriters and just got an underwood leader model. A few of the keys are sticky. I've already tried cleaning it thoroughly with rubbing alcohol and gently bending some of the keys that may be out of line but some of the keys are still very slow. Any suggestions on what might be wrong?