Annies ult

Noticed that when me and a friend of mine whos new to league were playing vs bots yesterday that if you play as annie that we were only able to use her ult once a game. Every so often i could use it two or three times but usually Its Just use it once and then it never comes back. Idk if its just in bots or if its normal games as well. I will be testing it more tomorrow. Ill try to figure out what circumstances make this glitch happen. But i figured id just let you guys know that there is a bug.