Help with drum brakes loosening after a week

[chrisofknives]

I recently replaced the shoes on my 2008 liftback and the breaks were great for about a week after we changed the shoes. Gradually throughout that first week, the e brake, and brake pedal both loosened up, to the point of the ebrake not catching the back wheels at all, and I had to put a cinder block behind my back wheel in my sloped driveway.

We jacked it up again, and tightened up the star wheel, made sure the wheel only made one rotation after adjusting, and everything seemed fine...same issues after a week again. It gradually becomes more loose. Any ideas? Break fluid is good. No leaks. Not sure what to do...