Rustle in the Bushes:
The LEE die is a collet assembly (DUH!). As such it has two taper surface that make it work as the die is pushed up by the press ram. Since LEE very often chooses the wrong materials for their products (and this die is no exception) eventually the two tapered surface (inside the die and the collet itself) gall making the die stick during use and not drop the case easily.
Polishing the taper surface on the collet can do nothing but good and using some light oil on that surface, replenished regularly, can preclude or delay the eventual galling that may occur.
In general neck sizing only works for awhile and eventually the cases, after many reloadings, will have to be full length resized. So don't throw away your full length resizing die. Also be aware that full length resizing is pretty much mandatory all the time for any self loading gun (semi-auto) or pump gun as those action have very little camming force when the bolt closes and a tight case fit to the chamber will cause jamming. Bolt guns not so much.