Sticky cases after a few firings are a good sign of too much pressure.
More common with neck only sized cases that are on the soft side; even with normal safe loads.
A way out of square bolt face also compounds the problem because the first time the case is fired, its head takes the angle of the bolt face. It's not squared up when resized. When it's neck or partial neck sized, reloaded then chambered 180 degrees out from when new, the bolt binds. Firing that round tends to stick up the bolt again.
I'd need some detailed dimensions on the cases to do any further reasoning as to why they stick. Case headspace, from new to first firing and after each sizing would be the best place to start.
Also, set the cases on a flat surface on a table set into the corner of a small square. Then spin them about their head axis. If the case mouth center spins around in a circle, the case head's out of square.