Voice or Video Call not working, Error Can not Place a Call with yourself

### Steps to reproduce

1. Where are you starting? What can you see?
Created a new DM direct message room, messaging back and forth works, but can NOT initiate an Audio or Video call at all. Neither of the two of us in the private DM room can initiate a call. I am using Element Desktop App and NOTHING happens when I click Voice or Video buttons (see https://github.com/vector-im/element-web/issues/22331 ) and the other person using ANDROID Element App is getting an Error popup saying Can not place a call with yourself.

So we can chat via text/typing, but neither of us can initiate audio or video call at all.

We are both connected to the SAME "Dendrite" Homeserver (latest stable main/master from 5/23 github).

I'm using latest Element Desktop app: Element version: 1.10.13
Olm version: 3.2.8

Other person is using (Android 8.1? on Note9) with Element Android App version 1.4.16-dev and Matrix SDK 1.4.16 and Olm 3.2.10

### Outcome

#### What did you expect?
I expect the Audio/Video to work. TURN server is installed and it has worked before in other rooms etc.
#### What happened instead?
It doesn't work, as described already.

### Your phone model

Samsung Note 9

### Operating system version

Android 8.1

### Application version and app store

1.4.16-dev and Olm 3.2.10

### Homeserver

Dendrite github

### Will you send logs?

Yes