iOS Calling doesn't work on Wi-Fi

[Overdrive4954]

Steps to reproduce

Self-hosted (Docker) synapse server hosted and accessed internally over VPN.

1:1 calls work from MacOS Element on wi-fi to iOS Element on cell network, from iOS Element to iOS Element on cell network; same when both cell network and wi-fi are connected. When an iOS device is only on wi-fi (airplane mode and wi-fi connected) calls don't work to or from any endpoint.

verified everything else works - can send messages, browse the internal and public web, &c. and call notifications work, but will not connect to or from any iOS device only on wi-fi.

coturn server is running in another container, and there is no incoming public traffic to Synapse server, but outgoing public traffic isn't restricted.

New setup, and all phones/laptops are running newest Element.

Outcome

What did you expect?

Calls to/from iOS Element on wi-fi to connect, just like call to/from MacOS Element on wi-fi.

What happened instead?

Calls always notify distant end, but do not connect/no audio

Your phone model

iPhone 15

Operating system version

iOS 17.6

Application version

Element 1.11.16

Homeserver

Synapse 1.111.0

Will you send logs?

Yes

[Overdrive4954]

nevermind, may have been a combination of turn/wifi calling issues