Right rear sticking

Hey gang... So one of the projects this winter was getting my rear end housing fixed. When we started taking things apart we realized the right rear axle seal was leaking. So there was fluid in the drum and on the shoes. When it all went back together everything seemed fine for about 20 minutes. Til the brakes got hot. Then when you would almost come to a stop you could feel the right rear trying to lock up... Like the brakes would grab.. Made a god awful racket. Car would sit and cool, take it back out all would be fine til it got hot again....

It occurred to us we forgot to clean the inside of the drum or the shoes. So we assumed it was the residual gear oil causing this issue... So we changed shoes, and I cleaned the drum, even took some 80 grit sandpaper to it... Drove the car today. A good bit further and thought all was fixed. Suddenly the right rears back to grabbing. Get it hot enough when you take your foot off the brake to pull out it will still be grabbing and making noises ..then let's go.... It never did this before we tore the rear down,,, it makes no sense to me... Any thoughts? Could it be us getting the drum hot when it was still lined with gear oil messed the drum up...

I thought maybe it was a wheel bearing or something cause of the noise and the way it feels when it does this... But that made no sense as a wheel bearing that's bad would be symptomatic all the time right? Help... I'm frustrated