RAYZOON

Ok, I'm trying to lock several measures so the brain will not overwrite. I click it but it doesn't light up, nor does it appear to work.

Are you using the lock symbol (on the far right) or the "lock" word (on the right side of the top row)? The former is to lock the respective part's groove, accent, or fill. The latter locks the selected individual hits.
HTH
J.L.

I'm clicking on the word. It doesn't seem to lock anything.

The "lock" word locks a SELECTED hit or hits.
HTH
J.L.