HTML heading problem in WD 11

[avguy]

Hi - I'm using WD 11 premium. When I enter the HTML H1 - H6 tags, they are visible when I preview the webpage.
Attached is a screen shot of whats happening.

Please note that I did not have this problem at first when it was a single 955pix webpage.
This has occurred after creating a mobile variant and I cant figure out the problem.
Thanks in advance for any help with this.

Mike