Caching is almost certainly an issue on your site. That’s why I still see cached files that are not part of WPFC.
Screenshot for proof:
View post on imgur.com
Unless it is a complete coincidence that:
- my very first instinct was to tell you to clear your cache
- That you said it worked when logged in but not with logged out (which is a common indicator of a caching issue)
- that you said it started to work after you got Bluehost to clear their cache
- even though you say you have caching disabled for everything except WPFC, I can still see the cache files created from Fast Velocity Minify in the source code.
And on top of that, from your previous reply
I have tried removing add-ons one by one to see if any of them is causing the problem. After that, the black start button appears on the page, but when I leave the page and come back, the start button has already disappeared from the page.
Which makes perfect sense if the issue is a cache issue. When you are not loading from cache, it works. Then you leave and come back and are now seeing the cached version, which is broken.
So what to do? Go scorched earth.
Look at any plugin you have installed that has anything to do with page caching or minifying assets. If I didn’t dig through your rendered source code and google search the footprint of the URL to find that you are using Fast Velocity Minify, you would have never looked there. So make sure you don’t have yet another caching solution installed on your site. Also double check bluehost. Even if you have it disabled, the previously generated cache might still be active until you clear it. Same with WPFC.