loud continuous "helicopter" noise during video call from element-desktop to element on android

### Steps to reproduce

The sound only occurs during video call, NOT during audio-only call. Video works fine with no issues.
The sound can only be heard on the Android device. It makes it almost impossible for userB to hear sound coming from userA.

userA: Garuda linux, Element ver 1.11.20 Olm ver 3.2.12
userB: Android 9, element ver 1.5.18 Olm ver 3.2.12

I could upload a recording of the sound if necessary, but please confirm this would be helpful before I go to the trouble.
I can try to provide logs if requested but of what and which logs?

### Outcome

#### What did you expect?
Relatively clear audio.

#### What happened instead?
userA cannot communicate with userB (except perhaps through sign language)

### Operating system

Arch linux & Android pie

### Application version

olm 3.2.12 , element 1.11.20 / 1.5.18

### How did you install the app?

AUR / f-droid

### Homeserver

matrix.org

### Will you send logs?

No