Got it to work!

Ok, after a few hours of pulling my hair out with a test site here is what I found...

1... With my main site, it had the previously mentioned problems with the BuddyBoss Boss theme. However, if I switched to any other theme there was no problems which let me to believe it was the Boss theme.

2... With the new test site I had only the boss theme, buddypress and SimplePress.  In this case it worked just fine. Which then led me to believe that there is a plugin that caused a problem only in the case of = "Unknown plugin" + "BuddyBoss theme" + "Simple:Press". - Began removing most of my plugins one by one. But nothing changed, same problem.

3... Began trying different settings within Simple:Press. FINALLY, tried the setting of "Integration - Theme Display Options - Limit forum display to within WP loop" and everything fine. 

So now that I have finally found a solution, my question is: "Is using this setting ok? Without any side effects?"

 Hello team!

So sorry for my bad english.

Thank you dave, but your tips didn't work for me.

So left panel without simplepress : http://reseau.emploiculturel.net/

Left panel with simplepress: http://reseau.emploiculturel.net/forum/#

(try to use it to consider the issue)

But i'm not premium member of simple press and don't have buddypress pluggin... I test simplepres with boss theme before buying membership...

I just try  Limit forum display to within WP loop, but maybe forgot another setting?

Thank you!

So sorry, it's not the same issue, i don't anderstand because my bad english.

Because of a false setting, unregistered user can't see the issue..

Now you can see...

And so, in the footer of the page, you can see "view as mobile", or "view as desktop". Only "view as desktop on simplepress page.

And if you are in mobile view, on simple press page, nothing happend with two icon on the top left and right corner...