Cold/Lightning Infusions Support for Charged Staff

I noticed that cold and lightning infusion isnt supported by charged staff. When i have the item in my inventory and hover the mouse pointer on it theres a screen that opens taht shows supported skills. on that list theres an X marks which signifies its not supported. Althought players can still insert cold and lighting infusion as support gems to charged staff, is it effective? based on what i can see it shouldnt. I need clarity whether it will work with charged staff or not. Is it just a visual bug that it has an X mark?