Not clear if you have a manual or automatic?
I assume manual from mention of Neutral.
It is most likely that a rear brake shoe is sticking, when was the last time they were serviced?
Could be they are heating up when driving(which they shouldn't do), when you park and set the E-brake the hot shoes are "welding" themselves to the drum.
E-brake would "feel" fine, and release fine but the shoe is NOT releasing, so there is a pop noise when you actually move that drum as the surfaces are forcibly released.
Dragging shoe(heats up) could be slave cylinder issue on that side
Block a front tire
Then put trans in neutral
Jack up each rear wheel and turn it, see if one is dragging
And just a heads up for e-brakes since winter is coming
E-brake cables can get water inside them, so good idea to spray lube inside them if possible, the CABLES not the brakes, lol, it displaces any water
You set e-brake when you get home in the evening, then it sits overnight, you release e-brake in the morning but...........cable is frozen solid so e-brake is still set, WTF
Outside of building a fire under the truck, lol, there is no easy way to fix that, heat gun on the cables is probably only way to get it to release, or wait until it warms up outside, say JUNE/JULY in some places
This is not the brakes freezing, it's the e-brake cables
And these don't "break loose" like above stuck shoe would, so you can then drive, you are stuck until you can thaw out the cable that is holding the brakes on.
Just a heads up about using E-brakes in the winter months