Fuel Issue with 49 cc GY6

[kram6319]

Hello,
I have a fairly new 49 cc GY6 with 700 mi on it. I bought it new no issues so far except this one. When I stop to get fuel, I am careful of 2 things, 1, that I do NOT overfill the tank, and 2, I use 93 octane. The past three times I have gotten fuel at the same place Marathon, once I fill up, it is VERY HARD to get restarted. I got fuel today, and it almost would not start. It took six tries to fire up finally. Any reason why? Once it started, it runs great no issues at all. I took it on a 15 mi ride today and stopped after I got gas and it restarted 1st try. It seems something happens when I fill it? I also usually get fuel when I am just under half a tank. When I got home, I let it sit for 20 min and went out to start it and again, it started 1st try. Any suggestions on what to look for? I sure do not want to get stuck next time.