I'm really thinking it has to do with the fact that we bought it before being able to use that skill. Mine does the same as yours. Sometimes it seems to take the skill point and shows as activated but as soon as I go on cannon or tp somewhere I have a skill point available again. Was so bad that it didn' teven let me use that skill point at all until I unlocked my next item by reaching level 8. Weird stuff. Good luck to you Princess. You play TT as well I think I read? Are you on test?
Just wanted to add that I asked Disney if there was any way I could clear my inventory and get rid of the grape shot ammo I bought and they didn't respond to that for me either. I think that would fix the problem. Hmmmm Well I love my Firebrand now and will probably work on upgrading that and my reloading time anyhow