I am working with @richard_wang on this. @meaton The most common cause of issues like this is both proxy's trying to handle the same flow and failing. For example, are you trying to handle UDP flows in both of your providers? If I'm not mistaken an App Proxy can't handle DNS flows and only a DNS Proxy can, so I don't see how this could be the problem. We will confirm this. I would try setting up your NEAppProxyProvider to only handle TCP flows and see if this makes a difference. We have tried this and still no luck. We will keep trying to solve this and if you have any clues please let us know. Thanks.

@meaton I have done that. I eagerly await a response.