Just finished my first game after the Hextech went live, and I have a little note on the bottom that says I can't earn Hextech shti because of behavioral issues. I finished my 20 game chat ban like 2 months ago, and probably a hundred games or so. So why can't I earn anything? On the rito info page it says that if you are currently in a restriction you can't earn them... but why doesn't this work for me? any ideas or anyone else experience this? 
It might be set up the same way season rewards are, in that any season offenses effect the distribution of rewards. I don't know man, it doesn't make sense to me either (i havent gotten a restriction tho), but this is Riot essentially giving away stuff for free, so they most likely are going to be very picky about who they allow to take part in it.
No. Players who are chat or ranked restricted or currently banned from play cannot earn or unlock chests through Champion Mastery. Once they’ve reformed, they’ll be eligible for rewards again.
http://na.leagueoflegends.com/en/news/game-updates/features/hextech-crafting-now-live-na Under the FAQ
2 months of playing doesn't even downgrade your penalties. I would guess maybe 3+ months after your last restriction, you might get cleared to get chests.
