Hello Rob,
Thank you for your questions.
There is no such setting per se, i.e. the Host is supposed to be online provided there are no issues or factors that would prevent it from doing so (either on the Host side or Viewer side). If ALL of your Hosts are not shown as online in Viewer perhaps the issue is on the Viewer side which cannot connect to our intermediary server for some reason (or your self-hosted server if you use one).
This Internet-ID connection troubleshooting guide can help you figure out where the problem might be
https://www.remoteutilities.com/support/kb/cannot-connect-using-internet-id-connection/ .
Feel free to submit a
support ticket if the issue still persists.