Can't find SabNZBD - Timing Out

**Sonarr version (exact version) **:
Mono version (if Sonarr is not running on Windows):
OS: linuxserver/sonarr:preview docker container
Debug logs:
[Error] Sabnzbd: Test aborted due to exception

[v3.0.3.928] NzbDrone.Core.Download.Clients.DownloadClientUnavailableException: Unable to connect to SABnzbd, The operation has timed out.: ‘’ —> System.Net.WebException: The operation has timed out.: ‘’ —> System.Net.WebException: The operation has timed out.

at System.Net.HttpWebRequest.RunWithTimeoutWorker[T] (System.Threading.Tasks.Task1[TResult] workerTask, System.Int32 timeout, System.Action abort, System.Func1[TResult] aborted, System.Threading.CancellationTokenSource cts) [0x000f8] in <91935ad653254a93b9d73a9f8f2f7a2d>:0

at System.Net.HttpWebRequest.GetResponse () [0x00016] in <91935ad653254a93b9d73a9f8f2f7a2d>:0

Description of issue: I am running SABnzbd and Sonarr 3 from a docker-compose file. Today I switched from Wifi to Ethernet and had to change the IP address from .77 to .10 on the Macbook that is running the containers.
Previously this was working fine with the SabNZBD settings in Sonarr pointing at Host: and a port of 9501. Therefore thr only change i made was to change the host to, same port.
After the change I did a docker-compose down and then a docker-compose up -d
I went back into Sonarr to the Settings > Download Clients page and brought up the Sabnzbd page to make sure the ip address change had taken - which it had.
API key on Sabnzbd hadn’t changed either, but when I click on the Test button I get ‘Unable to connect to SABnzbd’
Logs shown above were pulled from Portainer.
I get the same type of error when trying to use NZBhydra2 as the Indexer within Sonarr.
NZBHydra2 can access Sabnzbd OK and can send jobs to Sabnzbd for downloadng, so it does look like something speific to Sonarr