Looks like it was two things.
First: A chord combination on trigger for any additional mouse 2d input actions will prevent any without from triggering. If the chord combo is removed, both fire along with the mouse down.
Fix: Separate any extra input actions away from the player input actions into a different Input Mapping Context file.
Second: The original Input Mapping Context was still being activated in another class. Replacing that mapping with the extra mappings context with the above fixed the problem.