Sounds like the evap canister got filled up. I dont have any experience with them, but I have heard stories about people with them and what can happen when too much gas makes its way into the canister.
Apparently if you fill it with gas the carbon inside the canister will turn from powder to a solid and not allow the gas tank to breath. What happens then is as gas flows to the carb negative pressure builds between the canister and the gas tank making it so that fuel flow from the gas tank to the carb is more difficult. Ultimately leaning out the engine so it runs like crap.
I would probably see if someone with a canister TW can verify this is possible on our bike though. Just an idea I had from reading your post. Not really sure what the fix would (not sure if you can just replace the powder or the whole canister) if this is your problem. Then again, you really don't need the canister to run the bike but it does have some perks apparently I know Lzrdbreath likes his.