WebSocketException: Connection to '<url>' was not upgraded to websocket, HTTP status code: 403

[pgulegin]

Using version 1.3.9, everything was working as expected.
1.4.0 appears to have this breaking change.

In the code/exception below, 'url' denotes the original url I used.
However, 'url_modified' is my original url, but it has been modified to include a port number and a hashtag.

So, if my original url was something like... https://www.google.com/Channels/Support
Then, the new url is... https://www.google.com:0/Channels/Support#

Code

    connection = HubConnectionBuilder()
        .withUrl('<url>',
            options: HttpConnectionOptions(
              accessTokenFactory: () async {
                return fetchAccessToken();
              },
              skipNegotiation: true,
              transport: HttpTransportType.WebSockets,
              logger: _logger,
              logMessageContent: true,
            ))
        .withAutomaticReconnect(retryDelays: [1, 3000, 10000, 30000]).build();

Exception

[ChatPageViewModel] WebSocket try connecting to 'wss://<url>'.
flutter: WebSocket try connecting to 'wss://<url>'.
flutter: 2025-01-20 17:24:23.514104 ══╡ EXCEPTION CAUGHT BY CHATPAGEVIEWMODEL ╞═════════════════════════════════════════════════════════
The following _Exception was thrown WebSocket connection to 'wss://<url>'
failed: WebSocketException: Connection to '<url_modified>' was not
upgraded to websocket, HTTP status code: 403:
Exception
════════════════════════════════════════════════════════════════════════════════════════════════════
flutter: WebSocket connection to 'wss://<url>' failed: WebSocketException: Connection to '<url_modified>' was not upgraded to websocket, HTTP status code: 403
flutter: 2025-01-20 17:24:23.514711 Another exception was thrown: Exception
flutter: Failed to start the connection: WebSocketException: Connection to '<url_modified>' was not upgraded to websocket, HTTP status code: 403
flutter: 2025-01-20 17:24:23.515032 _ChatStore() startConnection() WebSocketException: Connection to '<url_modified>' was not upgraded to websocket, HTTP status code: 403

Thank you.