Hi losses,
FloatingPawnMovement doesn’t work with AIMoveTo. You should use AddInputVector as you pointed it out yourself. If you have created a blueprint based on the character which itself inherits from Pawn, then you shouldn’t have a problem using AIMoveTo or SimpleAIMoveTo as long as you have a NavMesh in your level.
You can read my other answer that explains in details how to use a FloatingPawnMovement and how to move and actor without a NavMesh in here.
Hope this helps.