Add Movement Input does not work on any pawn that is not controlled by the player

Add Movement Input does not work on any pawn that is not controlled by the player. Note: this worked in 4.7.6 and earlier.

Test project attached. In it, the Player Controller controlled by the active Player attempts to use Add Movement Input on a pawn controlled by a separate Player Controller. Though all the references are correct, it does not accept input.

Reproduced in 4.8.3 binary, 4.9.2 binary, and Main (CL 2709700). This is a regression: the same setup worked as expected in 4.7.6 and earlier.

1. Open the attached project
2. PIE with a dual stick controller
3. Move the left stick to move the LeftStickCharacter
4. Move the right stick to move the RightStickCharacter

Result:
The RightStickCharacter does not respond to Add Movement Input