Manually Painted Vertex Weights don't export to FBX, but auto-weights do I'm exporting using the AutoRigPro exporter. In Blender, the weights look fine (the first image). However, After auto-weighting to my rig, I needed to do some manual painting around the wrists to fix deform issues. Then on export to FBX I get the issue you see in the second image.

Any vertex I painted manually or modified in the slightest with the blur tool doesn't seem to export properly.
I checked and the bone I'm weighting to is the correct one, and is exported. The weights are normalized. There are no more than 4 weights per vertex. Any idea what's going on here and how to fix it?
Removed the link to the source file because I solved the issue.
This was due to conflicting vertex groups in the ARP exporter. To fix it, I removed vertex groups that didn't match the secondary controller mode for ARP (which were added in a different bind session set to &quot;none&quot;). In my case, I needed to remove the following groups because my current bind is set to &quot;twist:&quot;
-arm_stretch
-forearm_stretch
-arm_twist
-forearm_twist
-thigh_stretch
-thigh_twist
-leg_stretch
-leg_twist