it seems the message is right.
If I visit your site at https://vietvelo.org/ I see a page without style.
Be careful, I suppose you see a normal page because you are logged in, people who are logged out see a cached version that is broken.
Try to see your website using a desktop with a browser where you are not logged in.
Then, if I visit the same homepage after adding a query parameter to the URL I see it right: https://vietvelo.org/?dffdsf=sdfsdlklk. This is because this last one is without cache. Then, if I visit again the same URL (https://vietvelo.org/?dffdsf=sdfsdlklk) with a mobile, I still see the desktop version on mobile. I need to change something, e.g. https://vietvelo.org/?dffdsf=sdfsdlklkzzzz gives the mobile version on mobile.
So, you have a problem with the cache. Your caching system doesn’t distinguish between mobile and desktop.
Check the settings of WP Fastest Cache, but probably the problem is caused by the cache of the server, or by a CDN, or more probably by the mu-plugin endurance-cache.php.
Bluehost usually installs a mu-plugin for the full-page cache. That mu-plugin is always a pain for a lot of users, and it doesn’t work properly. Be sure you don’t have it. If you have a real caching plugin like WP Fastest Cache you really don’t need that mu-plugin.
Go to Plugins => Must-use. Do you see a mu-pluin with a title that looks like “Endurance Cache” or something similar?
You can also check via FTP or with a files manager in wp-content/mu-plugins. If you find a file with a title that looks like endurancec-cache.php or something similar, it means you have this kind of cache. If so, you should also see an action link in your admin top bar to delete the cache. Click that link, and then via FTP delete the file endurance-cache.php (or how it calls).
@rapidcarbon still me.
It looks you also have 10web cache.
If I inspect elements I see the comment “Cached by 10web”. So, this is also another layer of cache that may not distinguish between mobile and desktop.
I have deleted /wp-content/mu-plugins/endurance-page-cache.php, and also disabled 10Web Booster plugin and deleted all caches in these folders wp-content/cache/all and wp-content/cache/wpfc-minified. The problem still exists. whatever do I have to do?
Thank you so much for helping me in this matter.
I still see the same page and the comment <!– Cached by 10Web –> when I inspect elements.
I suggest you clear all the cache that you have on your server.
Maybe ask also for help from Bluehost.
Thank you. I reached out to Bluehost and they cleared all cache on the server. Everything works now.