It's the same on both Mobile and Desktop. If you need any assistance do let me know.
The menu is showing the same on my both devices Mobile and PC. Can you please try in a private window or clear browser cache.
I don't think you are clicking on the home page links for testimonials and the cookbook. Even on the "customize" section of the shopify theme its showing that it is doing something different on the treatments link v the others.
These 3 buttons - 2 are right (2 & 3) and 1 is different.
1) Pressing on "mi:skn treatments" from home page - drop down menu blocking page
2) Pressing on "Client Testimonials" from home page - no drop down menu blocking page
3) Pressing on "recipe books" from home page - no drop down menu blocking page