Vantage menu position displaying incorrectly sometimes.

The main menu for my website displays fine on all pages except one. On this page it acts as if the screen is much wider and stretches the menu so the logo and the menu items are pushed to the edge of the screen.

Here are some screenshots:
Correct
incorrect

Removing all custom CSS didn’t help. And I’m afraid I’m out where I can’t swim.

I hope you can help. Thank you for your time,

Best regards,
Rasmus