I Don't Want My Friend's Masteries in Dynamic Queue

The dropdown menu to select a mastery in dynamic queue shows a friends mastery pages under the following circumstances:

1. Start a dynamic queue (I was in Normal Draft Pick)
2. View a friend's Mastery pages on their summoner's profile (via the friends list)
3. Click through your friend's mastery pages
4. Once a queue "pops" and you are in champion select, your mastery page selection dropdown menu shows your friend's most recently viewed mastery pages instead of your own presets.
5. This bug continues across games
6. The number of masteries visible is the same number as your friend's (the dropdown menu contains a mastery page if and only if it is your friend's page)

Hotfixes I used:

1. Selecting Edit allows you to select from your own mastery list (and extends the dropdown menu of masteries to include some of your own; for example, if your friend had 3 mastery pages and you had 10, the first three masteries in the dropdown are rendered as your friend's, but the last seven are rendered with your own names)
2. After selecting one of your own mastery pages from Edit, you may scroll (if you have enough preset mastery pages to do so...) to "repaint" the list to have your masteries. After Edit is selected, I BELIEVE that your masteries are actually used instead of your friends, but the names painted on the dropdown remain the same as your friend's list of masteries, due to dodge penalties I can't accurately test this.)
3. Restarting the client stops the bug, but only temporarily

I have no idea the consequences of "editing" a mastery page that is rendered as my friend's page... I sure hope I didn't change their masteries...

Thanks for listening! -bdb3000 (SudoCowdancer)