New client lags on champ select

As the title says, it lags on champ select. I remember I tried playing ARAM on it the other day and it froze for 10 seconds cause someone sent a trade for my champ just as I entered. Funny thing tho, it's laggy for about the first 10-15 seconds upon just entering champ select then everything starts working fine as normal no lag. What's up with that?