Istio blocking communication to external service

I have a setup where one of my pods needs to talk to a pod outside the mesh but Istio doesn’t seem to allow this to happen. When both pods are outside the mesh they can talk to each other without issues so I have no reason to believe that there’s a problem with a malformed request or similar.

As soon as the first pod is brought into the mesh the request to the second pod invariably times out. global.outboundTrafficPolicy.mode is set to ALLOW_ANY so I don’t see why the second service should not be reachable. FWIW I am trying to make an https request.

Does anyone have any idea why this would happen and is there a way to debug this, I can’t see anything at all related to the failing request in the Istio logs?