friend's masteries showed up in my ranked game's dropdown options

I was browsing a friend's masteries when our ranked party game started and my masteries dropdown showed his named masteries. If I clicked the pencil button next to it I could select mine and if I selected the dropdown after it would show his again but limited to the number of mastery pages I had setup. It continued to do this for each game. I havent tried again since restarting the client.