Can you clarify what you are trying to do? Are you on the Mobile site trying to link back to the full site?
If so do something like this.
From Mobile > Full
example.com/page/?view_full_site=true
From Full > Mobile
example.com/page/?view_full_site=false
Note the ? in between.
I just tested setting the cookie with a subpage and it worked fine for me. I also updated the mobile esp library so maybe update the plugin and try that.
If you are still having trouble please provide a link to your site.
