Laravel Session Destroying after Redirect Back from PayPal

Hello,

I am facing Problem with my Web App built in Laravel 5.1, I put a Pay with PayPal button on my website.

When user click on it , It redrects user to PayPal Payment page and user Pay the amount after that PayPal redirects back to my web app but sometimes Laravel Session destrol and log out the user but sometime not.

I have also tried session from FILE to cookie. but doent help me.

Can any one please guide me here.

Thanks.