Q: Brakes catch while driving

I drive my truck to and from work about 15 miles through several steep, winding hills and often stop-and-go traffic. The rear drum brakes are less than 2 weeks old - all new hardware, shoes, wheel cylinders, and drums. When I drive though, they feel like they're catching. I can especially feel it when I'm coasting - it's just... catch, go, catch, go or soft brake, go, soft brake, go. Maybe it's the bearings? I can hear it though, the sound of the brakes squeaking/screeching on the catch/soft brake. I hope this is making sense. It's enough to make me look like I'm doing a soft head bang in my car when it happens - lol. No smells, just the squeak/screech and the catching on brand new drum brakes.

My car has 181470 miles.
My car has an automatic transmission.