Mesh shifting when imported from Blender to Unity

[myfutureistosleep]

I am currently trying to import a rigged mesh from Blender and the “toe” parts, see image, keep on slipping/disconnecting from the model and I do not know why.

The issue is not visible in Blender and there are no weird, hidden keyframes that might cause this.
The mesh is intact in Unity so the only thing that could be causing this is the armature/rig.
I have included a screenshot of the mesh and rigged model side-by-side for reference.

Screenshot 2023-09-06 191257.png failed to upload, try again

[myfutureistosleep]

I managed to fix it by setting frame 1 of the idle animation to as the keyframes for frame 0, then setting the animation to play from frame 1 in Unity.