Normally, the main factor for the Connect feature to work properly is to be sure that the IP addresses for the tablets and the computer (that Connect is being used on) are all on the same subnet.
If the computer that's being use to access Connect is still unable to connect, please be sure that the computer is able to connect to the edredi tablet on ports:
using the IP address that the computer reports to on the edredi portal. The reason for this is because the Dashboard uses HTTP protocol over these three ports.
if your network uses a proxy to access the internet, both the computer as well as the tablets need to be configured to "Bypass the proxy for Local IP addresses". For the tablets, this can be accomplished by entering the URL or IP address in the Exclusions field when creating the Proxy QrKey in the QrKeys screen of the edredi portal.