Made a model, rigged it using rigify, and exported to unreal engine 4.27. When testing out an animation the result looked fine but it was “pinching” at the wrist in a way that doesn’t show up in blender. Any suggestions?
I have no experience with exporting rigify rigs or animations to UE. But afaik, UE doesn’t have bendy bones, so it will use every bone as one solid block. But rigify uses bendy bones for deforming bones. It looks like you have transformed the tweak bone on the wrist to correct some deformation in the area (the wrist has a slight curvature in Blender). The behavior of tweak bones is based on bendy bones, so the effects they do will not be correctly replicated in UE. This is my theory. 
Doesn’t Rigify have an option to use a chain of several bones as opposed to one bendy bone, for export purposes ? or am I thinking of a different autorig ?