Sequencer losing bindings when undoing assign actor action

Noticing that when I undo assigning an actor it no longer plays back the previously assigned actor.

1. Open QAGame
2. Open QASequencer
3. Press 2 to jump to the 2nd bookmark
4. Open Sequencer_AssignActor
5. Right Click on SK_Character_AssignActor
6. Select Assign Actor > Select SM_Prop_AssignActor
7. CTRL+Z to undo
8. Play back the sequence

Result: Character no longer animates across the floor.