Rigify (DAZ) to UE4 unusual animation behavior

DAZ character directly imported into Blender 2.82 and bound to a Rigify rig with the help of this nice plugin:

Everything works fine until I import an animation into Unreal Engine 4. The head mesh is scaling whenever the controller tweak_spine (see image below) is moving. However the head is perfectly fine inside Blender. No scaling at all.
Do you know how to solve this? I exported using the FBX format selecting the character mesh first and then the Rigify controller rig.

I’ve also tried to install some of the Rigify to UE4 exporters. But they do not appear in the plugin section after pressing the install button. Here is one that I’ve tried to use: https://gitlab.com/ioflowstudios/rigify-ue4-exporter It also doesn’t work with Blender 2.80.

Same thing happens when you just reimport back into Blender. Are the IK bones not being baked at all?