Hi. Joining the thread after doing some investigation and not getting any insight beyond "this looks like a network" problem. I work with @kpalser so this comment is related to his problem. Summary: It would be nice if I could look at the packets on the wire. For me, to get that specific code, all I have to do on a server is accept the connection then close it. But that doesn't block the app from working once the server is fixed. This scenario involves a direct connection to the server. There's one difference in my lab versus the real world: the app receives that error with Cloudflare, which doesn't appear prone to closing the connection before negotiating TLS. When I tried breaking my server behind Cloudflare instead of being connected to it dirrectly, Cloudflare just returned one of its error pages, which means it's going past the TLS handshake. Given that this may be a network level error, is there a way to intercept network traffic from an iOS device connected to an LTE network? I don't even need the whole iOS network traffic. I just need the app's traffic. If the app needs some changes for this, that's OK. But I would need to see if there are FIN or RST packets on the wire itself. Thanks.