Masteries

So i was in champ select. And i had my mastery paged called "tank top" selected. but then for some reason, it hovered over something named "mastery page 14" but when i clicked edit, it took me to "tank top" but when i got into load screen, it showed that i had fervor of battle, when the keystone i should have had was grasp of the undying. when i checked na.op.gg. it told me i had a page selected called "adc/caster" and i have not owned a page like that for almost a year. for the record i did delete a mastery page in a champ select earlier in the night. i personally believe that caused a bug. its the only explanation i can think of.