Video call: Partners don't see me, but I see them.

[x] I have searched open issues for duplicates
[x] I am submitting a bug report for existing functionality that does not work as intended
[x] I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
[x] This isn't a feature request or a discussion topic

Bug description

When I or the partner start a video call, the partner cannot see me. The partner only sees a black picture with my profile picture. This problem occurs with different devices (not manufacturer-related). I see my partners perfectly.

I am not sure if the problem is also related to ticket https://github.com/signalapp/Signal-Android/issues/8685#issuecomment-484053653

Partners can see me with: Apple iPhone 8 (iOS 14.4) Samsung M30S, 4.14.62, Android 11

Partners can NOT see me with: Huawei Huawei P30 Lite (MAR-LX1A), 4.14.116, Android 10 Samsung A40 (SM-A405FN), 4.4.177, Android 10 Honor 10, 4.14.116, Android 10

Note: all devices are running Signal 5.4.12

Steps to reproduce

start videocall
activate camera

Actual result: When a video call is started, the partner does not see me. Expected result: When a video call is started, the partner sees me.

Device info

Device: Xiaomi Mi 10 (M2002J9G) Android version: Android 10 (Kernel 4.19.81) Signal version: 5.4.12

Link to debug log

Debuglog with Xiaomi Mi 10 and Huawei P30 Lite Xiaomi https://debuglogs.org/6b27114be8ea9fdebc078aa09e80509ca56cb78d32c77ff5057eda0d101e0d53 Huawei https://debuglogs.org/9e14eba990f608891315572abf9a3084560d0646fe4fe7354697391db0a0e545

signalapp / Signal-Android