Old post, I know. But I just switched my site from wordpress.com to www.ads-software.com and I’m having the same exact issues.
When I was on wordpress.com, while viewing from a mobile device the menu became a drop-down menu. Which was great. But after importing my site in to www.ads-software.com, I’m having the same issue as sustainable.
The search bar is on top of the banner image and instead of a nice drop-down menu, all the menu links are stacked on top of each other, taking up half the page.
If anyone has found a way around this, please help me out.