Why won’t the brush work?

I’ve been working on trying to fix my vacuum for weeks. The brush won’t roll for more than a few seconds before getting stuck. I’ve changed the vacuum belt, checked for blockages in the suction, cleaned all the possible blockages in the brush roller itself (took apart the white gear things), and basically pulled the vacuum apart trying to solve the issue without luck. The vacuum itself works fine battery wise, it’s just the brush that gets stuck. I really don’t want to buy another vacuum. Anyone got any ideas?