ZDoom

This is a known issue, it came from the sync'd code from GZDoom when there was a coding QOL feature added that allowed direct assignment of vec3's to their xy components.

It's a bit more complicated to fix because the error comes from conversion from one type to another and back and I am not really sure how Graf wants to tackle this.

Happening to me as well, seems every devbuild marked 1.12pre and after is affected, as the one immediately before has working movement. I thought something had gone seriously wrong with my system at first before I fired up Shadow Warrior.

You can not move in Duke3d, Blood and Redneck Rampage, and in Shadow Warrior you can only move on an axis, not in the direction you're looking at. Additionally none of the entities in either game move (Duke's ride only slowly falls to the ground for example).