1:1 Video call sporadically does not connect or connects only one side (black screen)

### Steps to reproduce

1. One person tries to call the other person
2. Element 1:1 call button

### Outcome

#### What did you expect?
a simple 1:1 video call established, both parties see and hear each other

#### What happened instead?
2 failure scenarios:

Scenario 1:
The call shows as "connecting", but none of the 2 participants see or hear each other. Instead, there is a black area where video would be and no sound is audible.

Scenario 2:
Side A hears and sees Side B, but the other side has no audio or video of Side A.

The interesting obersvation is that many times, when one or both Sides restart their Element Desktop app, it works again.

Please also let me know what logs you need from which participant to fix this really long standing issue.

### Operating system

across MacOS, Windows, mostly Desktop app it seems

### Application version

Version von Element: 1.11.31 Version von Olm: 3.2.14

### How did you install the app?

_No response_

### Homeserver

Synapse

### Will you send logs?

No