I've long been bothered by an issue where sprites get clipped by walls and floors, especially explosion effects and corpses. Today, I did some testing and narrowed it down to occuring under the shader renderer when a 3D plugin is running.
Typical, all shots clip through the wall:
They also pass though corners:
This happens in the original, with all plugins disabled except 3D scenery, at minimum resolution:
This is using the Feb. 26 2017 build under Debian 8 on a Nvidia Quadro FX 1600M