Habpanelviewer not connected

Hello, my Habpanelviewer always shows not connected.
But all data is sent from the HBV to OH. Battery status, motion detection works fine. But I can not send data to HPV.
Where could the problem be? Thanks for your help

Which version of HPV do you use? Are you connecting to a server install or openHAB cloud? Do you have password protection on your server?

I found the mistake. I had the connection hostname: 8080 specified. After I have given the IP address, the HPV has connected. everything works now.
Thank you