Sometimes, when you first apply 3Dseller's Store Designer, a part of your old eBay Store theme is still there, rearing it's ugly head (no pun intended).
Luckily, there's a simple way to hide this extra header.
You'll just need to change a quick setting in your eBay account:
1. Navigate to My eBay > Account > Manage My Store
2. In the left sidebar, choose “Display Settings”
3. Find the “Theme and Display” section then click “change to another theme”
4. In the far-left Theme menu, choose the “Easily Customizable.”
Then click “custom header only” and save.