Mastery Level Tokens

There have been 2 seperate occisions now where this has happened, although unfortunately i dont have any evidence of screenshots etc.

twice i have reached mastery level 5 with a champ, and got an S rank in that game. As i have hit 5 in that game it shows me the token i earned, however there is no token in my inventory. I'm not sure whether i should get the token, or whether it shouldnt tell me i have one as i have only turned 5 in that game. Either way i feel like this is an inconsistency that maybe needs looking at.

Thanks in Advance!