Oauth EU tenant URL seems not to exist in my test Auth0 domain

Hi, We are a vendor of a java webapp and are doing a POC for a client that is moving to Auth0 as their SSO.
I set up the account and downloaded the java EE demo login app. It logs on successfully, redirects to the callback OK with a code, but at the point of exchanging this code for tokens (RequestProcessor.exchangeCodeForTokens) I get java.net.SocketTimeoutException: connect timed out. Regardless of the timeout set.
Monitoring the HTTP post it appears to be attempting to post to

https://[my tenant domain].eu.auth0.com/oauth/token

and that domain appears unavailable. Other URLs in that domain

(eg https://[my tenant domain].eu.auth0.com/authorize)

seem to work fine.

The demo app is as downloaded, except that I am using port 8080 rather than 3000 and tomcat as the application server. Any help would be appreciated.

thanks

Andrew

Stack trace:

Caused by: com.auth0.exception.Auth0Exception: Failed to execute request
at com.auth0.net.BaseRequest.execute(BaseRequest.java:39)
at com.auth0.RequestProcessor.exchangeCodeForTokens(RequestProcessor.java:349)
at com.auth0.RequestProcessor.getVerifiedTokens(RequestProcessor.java:226)
… 28 more
Caused by: java.net.SocketTimeoutException: connect timed out
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)