The logic in your RootMotionCharacter_BP EventGraph doesn’t look right. How about creating 2 new float variables called UserForward and UserRight. Simply set UserForward to the AxisValue of the InputAxis MoveForward node, and do the same for the UserRight. Ok, so now those 2 variables always reflect what the user is trying to do. After setting EITHER UserForward or UserRight, have the exit point of both of those Set nodes merge together into the same input of your Cast node. From there, implement branching logic that does this:
If Moving is False, set MoveForward=UserForward, and MoveRight=UserRight.
If Moving is True, and either UserForward!=0 or UserRight!=0, set MoveForward=UserForward, and MoveRight=UserRight.
If Moving is True, and both UserForward==0 and UserRight==0, don’t modify either MoveForward nor MoveRight at all. No “Set” nodes for MoveForward and MoveRight in this condition.