Member-only story
Pick “other” as the option when selecting the SQL Server provider:
At first I thought this is what made it work. But this stopped working after a bit.
Later, I found out, use the test connection button repeatedly after a few seconds and once the connection succeeds you can move forward.
If you are using Unifi Routers make sure that the router is NOT blocking this connection. You can go to:
Settings > Firewall & Security > Signature Suppression (at the bottom) > Open Threat Logs
You will be able to allow or block the connection as well as the IP address. For some reason, these connections sometimes are blocked by Unifi.