My kapex has gotten very hard to rotate for miters. It feels like the bottom lock mechanism is grinding on the miter scale on the under side. The two torx screws for the lock release are good and tight (loosening them doesn't have any effect on the grinding, just makes the lock release not work). Can't see anything wrong. Tried to put some antisieze grease on the point where the mechanism contacts the bottom of the lower scale piece, but no relief. Not sure if I'm missing an antifriction piece on the black piece with the two screws, or if something else is wrong. Didn't see anything in the manual. Was OK, but just got really hard to move. Not sure what changed. Thanks for any hints.