Title is pretty descriptive. To replicate, create masteries during a champ select, they will not appear. They can still be selected by clicking their number, however, only other masteries already created will show.
I had this happen with runes, but it was in team builder. i joined a team builder, but while in lobby, i changed some rune pages. the changes after saving did not apply, and i would have to exit lobby and get reinvited, and sometimes i would even have to relog, for them to show up. I havent checked recently to see if it does it in the new draft mode, but since you dont choose your rune page until champ select when its too late to change them, its probably not still the case.
