Calls randomly do not use headphones when connected

#### Describe the bug.

When a Bluetooth headset is connected, video calls randomly refuse to use it even when explicitly selected.

#### Steps to reproduce:

1. Connect a Bluetooth headset to both iOS devices
2. Initiate a 1:1 (video) call
3. Verify that both devices have the headset selected
4. At least one of the two devices would probably behave as if no headset is connected (or worse, do not output any sound at all while recording using the internal mic)

#### Expected behavior

When a headset is connected and selected, it is used to emit and record sound.

#### Screenshots

N/A

#### Contextual information:

- Device: iPhone X, iPhone 7
- OS: iOS 14.3
- App: Element-iOS 1.4.9