Hi @kenneth79,
Thank you for reaching back to us.
Can you make sure that the “Mobile Background Color” option for your “Navigation” is not set to the transparent value please?
You can easily change this theme option in the Customizer. Just go to your dashboard and navigate to “Appearance > Customize > Navigation”. Then, open the “Style” tab and check the “Mobile Background Color” value.
This should solve your issue.
Regards,