Room members of encrypted rooms are unable to read my messages

### Steps to reproduce

1. An encrypted room is opened, which I already joined. For example, it can be either [this public room](https://app.element.io/#/room/#gadgetbridge:matrix.org), or a new room I just created, to which I invited a new account of mine.
2. I send a new message to the room.
3. Others let me know that they can't read my messages.

### Outcome

#### What did you expect?
Other members of the room to be able to read and respond to my messages.

#### What happened instead?
Other members of the room are unable to read my messages.

### Operating system

Windows

### Browser information

Firefox

### URL for webapp

app.element.io

### Application version

1.11.4

### Homeserver

matrix.org

### Will you send logs?

Yes