bobarr-api ECONNREFUSED with VPN

I've configured bobarr with my media directories and VPN credentials and am running with the `start:vpn` flag. Bobarr runs fine for a few minutes but when I try to start downloading TV, the episodes sit in transmission with 0 trackers (I have setup trackers in Jackett and am choosing torrents with lots of peers). After about a minute, I get a connection error message on the bobarr and transmission web clients and see this error repeatedly in the console

```shell
bobarr-api | 2021-08-19 16:25:22.577 [error] ExceptionsHandler - connect ECONNREFUSED 172.20.0.3:9091 - {"stack":["Error: connect ECONNREFUSED 172.20.0.3:9091\n at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1146:16)"]}
```

Any ideas why this would be happening?

Start by examining the bobarr-api and Transmission containers, the VPN-enabled startup path, and the connection to 172.20.0.3:9091. Reproduce the failure while starting a TV download and inspect the Docker networking and service logs. Done means the API and Transmission web client remain reachable and downloads no longer fail with ECONNREFUSED.

Written by the indexing model from the issue text.