Do I need to empty a cache somewhere?

We just checked and all works fine on mobile too. I think that's browser cache issue. Please open a private session browser in your phone when you check it. Also please ask somebody else to check it. I think that's device specific browser cache issue.

Thank you again for your help

I found some strange thing. The menu is only available on the forum home page, but it's not available on other pages. What have you done and what CSS codes are you using. This is not wpForo issue for sure, this is a result of your wrong CSS configuration. I have no idea what is this I see this first time. How can the same many appear on home page and disappear on other pages?

This is the only code that I have.
I got the bottom of yours

#wpforo #wpforo-wrap {
   font-size: 14px; width: 100%; padding:10px 20px; margin:0px;
}

#wpforo #wpforo-wrap .wpfl-1 .cat-stat-topics {width: 11%; } 
#wpforo #wpforo-wrap .wpfl-1 .cat-stat-posts {width: 10%; } 
#wpforo #wpforo-wrap .wpfl-1 .cat-title {width: 69%; } 
#wpforo #wpforo-wrap .wpfl-1 .wpforo-forum-info {width: 60%;} 
#wpforo #wpforo-wrap .wpfl-1 .wpforo-forum-stat-posts {width: 11%; } 
#wpforo #wpforo-wrap .wpfl-1 .wpforo-forum-stat-topics {width: 10%; } 
#wpforo #wpforo-wrap .wpfl-1 .head-stat-posts {width: 11%; } 
#wpforo #wpforo-wrap .wpfl-1 .head-stat-views {width: 10%; } 
#wpforo #wpforo-wrap .wpfl-1 .head-title {width: 69%; }  
#wpforo #wpforo-wrap .wpfl-1 .wpforo-topic-info {width: 60%;} 
#wpforo #wpforo-wrap .wpfl-1 .wpforo-topic-stat-views {width: 11%; } 
#wpforo #wpforo-wrap .wpfl-1 .wpforo-topic-stat-posts {width: 10%; }