This appears to be a regression issue in Unreal Engine 5.7 related to Control Rig playback inside Level Sequence, specifically affecting finger animations.
Finger controls work correctly inside the Control Rig Editor, and the rig evaluates without any problems. However, when the same animation is played in a Level Sequence, the fingers do not move at all, while the rest of the body animates normally.
What makes this behavior confusing is that after using Bake Animation Sequence, the exported animation contains the finger movement exactly as authored. This confirms that the animation data is correct and that the Control Rig is solving properly. The issue seems to be limited to how Level Sequence evaluates or displays Control Rig results in real time.
To confirm this is not a setup issue, I tested the same character and Control Rig in Unreal Engine 5.4, where everything worked as expected. The problem only appears in Unreal Engine 5.7, suggesting a regression in the engine.
Since the animation works after baking and works correctly in UE 5.4, this strongly points to an engine-level Sequencer issue rather than a rigging or configuration problem.