Mobile site has completely changed

Our mobile version of the site keeps changing to a random look. Not sure why. There are two photos of 1) what the site should look like (the white background) and 2) what the site is sometimes looking like for users (the dark background). I can send these if attachments are enabled.

Please let us know how to ensure the black background version of the site does NOT appear for users.

The page I need help with: [log in to see the link]