Error: lost connection to session.

Primarily this is a solution for an other problem, but maybe this helps if you're playing on PC:

Downloaded the programm Smart Port Forwarding and it as an Administrator. Than you can see a windows with an empty schedule. Right-click on the schedule and click on "Add new forwarding Port". A window is opening and select TCP and enter the Port "3659". After this, click on OK. Your option is now recorded and you can see it on the schedule. Now the same again, right-click, "Add new forwarding Port", but now choose UDP and the same Port.
Now you should have access.

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Otherwise ensure that you're using ethernet cable and check it. May it helps to deactivate Origin in-game.

Greeting!

My bad I am playing on the PS4. Sometimes it take 10 to 20 tries to get online. I shouldn't have these types of problems on a game that I have  spent over a $100 on.