Quick answer: Unity Animation Rigging constraints producing wrong output when Jobs system is enabled? Constraint update order requires single-threaded job; verify by disabling Jobs.
IK foot placement works in editor PIE. Build with Jobs enabled: feet point in wrong direction.
Disable Jobs for animation
Animator > Cull Update Mode = Always Animate. Some Jobs paths skip constraints; this fixes.
Or update constraints manually
For critical IK, drive via script in LateUpdate. Bypasses the Jobs-based pipeline.
File a Unity bug
Constraint-Jobs interaction has been an issue across versions. Confirm against latest LTS.
“Animation Rigging + Jobs is a fragile combination.”
If you rely on Animation Rigging, test with and without Jobs. The system bugs are version-specific; testing surfaces them.