Hi!
This topic may have come up in the past, but it seems WP Super Cache interferes with switching in that it will show whatever was cached first. In my case, I am serving a mobile theme that is a simplified version of the main site. If I start at the mobile site and click “Go to Full Site” (the desktop site) I do get the desktop site, but if I go to a page that is also on the mobile site, it goes back to the mobile version of the site.
I hope this makes sense but I expect people have come across this in the past?
Thanks!