Hi there,
Just checked your site on my iPhone 6s and not seeing the issue.
The problem here is likely that the logo is too wide so that when the phone screen isn’t big enough, there isn’t enough room for both the logo and menu toggle to stay in the same line.
I think the best solution in your case would be to create a second logo for mobile and only keeping the sun icon and life365 and remove other descriptions.
Let me know if this works for you 🙂