If Engine Lighting says ‘connecting’ in the top right corner of the GUI, try turning Engine Lighting off and then on again to see if that fixes the issue. It may also be worth trying to ‘Clear all bridge settings’ from the hue setup page and relinking.
Another thing to try (if possible) is connecting your Engine DJ hardware to the internet with an Ethernet cable to see if Wi-Fi signal could be the issue.
Is everyone using Basic or Pro mode?