Friend in the ARC Europe 2022.  Current in route from Bermuda to Horta.
Fleet One w/Sidekick Wifi router.
The router has a built in Firewall to block misc. outbound requests to save on data.  
They is a way to add exceptions and following the instructions a rule was added to allow outbound connectivity to 
178.79.175.12 which is yb.tl on port 443.
The skipper is reporting the following error.

"I got an error that in Expedition "The server name or address could not be resolved". Note - there is
nothing on the FleetOne hand set that indicates a data session is in process, for example, when I fetch email from Ocens."

I know this is not an Exp error but a Sidekick/Fleet One issue but was hoping someone here had some experience with this setup. Ocens, while typically very helpful was not able to solve the problem.