Roundcube does not refresh Inbox?

I use the latest roundcubeversion at the moment.
The problem the inbox is neither refresh at login nor on clicking the email icon on top.
The only way to see if I have new mails is to change the folder to trash an back to inbox.

A known bug or sth. like "works as designed" ?

 

Did you install the pkg from the ispconfig site?

 

On one server I did, on another I just fetched it directly from roundcube page.

 

RoundCube is still in alpha or beta stage, so I wouldn't expect too much from it...