What is the situation? Is there a message from the developers section about this?

The problem would be less bad if not the whole menu concept of wpForo would be so closed respectively insane from flexibility point of view!

To turn off the wpForo menu completely and use just a fancy menu on the WP base is the best and most sensible way.

Unfortunately, only then the quite fancy search and the "Bell" notification to solve. I have invested a few hours that " to tinker " and have not become more satisfied in the end. Because at the latest in the MOBIL view then things go wrong again ( ie shortcode in menu, put the "Bell" in a widget and that then via shortcode in the WP menu goes wrong in the mobile view).

So, if in over a year the priority continues to be on questionable things, but basic functionality is not achieved:
Then give us users a simple alternative WITHOUT getting widget sidebar (which you don't have in mobile) into WP menu.

Nothing against Java.Script solutions. But here somehow the solution is not in complexity but in simplicity of functionality.

Moreover, the problem is:

Because we can't define a "second" menu as a mobile menu - where you could then set the sub-menu items as main menu items - it's all very strange.

Good WP themes aka GP can do that and there any tinkering is no problem if something is not foreseen during development.

We are now at 2.1.6 - Then you mean 3.0 ?

I hope not. Folding menus have already existed before it was necessary to use smilies...

BUT you were able to fix this with a css

with the css code above, this only works on mobile devices that support the mouseover function

the dropdown function for click/touch is not exist

I don't get it :)

My Sub Menu Not Display On Mobile View

so have to wait until the 2.0 major version is released 😉 🤣 

The function to open the sub-menu is missing
on mouseover does not work 😉 

yeah, i get that. Is that by design, a bug? Why this happen?

The function to open the sub-menu is missing
on mouseover does not work 😉 

the submenu is hidden by default with "display:none" in mobile view

@media screen and (max-width: 620px)
#wpforo #wpforo-wrap #wpforo-menu .wpf-menu li > ul {
display: none !important;
}
}

if you want to have it visible use

@media screen and (max-width: 620px)
#wpforo #wpforo-wrap #wpforo-menu .wpf-menu li > ul { display:block !important; margin-left: 80px !important}
}
}

And YES, that is a real issue. A bug.