Hey guys, so one of the benefits (and reasons) why I slowed down slightly was so I would also have more time to do maintenance on the website. The desktop showing on mobile/mobile showing on desktop problem has been one of the most persistent, annoying problems that I have encountered to date. Some tech friends were convinced that it was SuperCache, but after turning it off and even uninstalling it the problem still persisted. After nagging at it for a few hours today (early release from work, woo), I -THINK- however that I have located the problem.
As it turns out, Bluehost uses a ‘server level cache’ method called ‘Varnish’, which in the configuration that Bluehost uses, is unable to differentiate between ‘mobile users’ and ‘desktop users’ when saving the ‘cache’. So what happened was if the ‘latest’ version of the ‘cache’ which Varnish had was a mobile version, even when a desktop user accessed the site, they would still be issued the saved, mobile ‘cache’, because Varnish didn’t distinguish between ‘mobile’ and ‘desktop’, only caring about whether or not it was the ‘latest’ cache or not. However, the ‘cache’ was not served to people who were logged in, which is why only people who were NOT logged in would encounter this problem.
At present, Bluehost is not willing to modify the Varnish cache (because they are trying to use identical settings for all their websites), so I have gone ahead and completely disabled Varnish. This is going to have two results:
1) Increased server load because the server cache is gone. I might have to upgrade the server to compensate, and/or get a second CDN to support Cloudflare, and:
2) Get rid of the problem with the mobile/desktop versions interchanging.
Anyhow, I’m not 100% sure, but I THINK this is it. So everyone, please keep your eyes peeled to see if the bad old problem still exists. If I can verify that it is gone, I will leave Varnish off, then pay extra if needed to make up for the extra server load with it gone. Thanks for your help, guys!