Describe the bug

When trying to schedule a message with an image attachment, the image is sent immediately while the rest of the message is scheduled as normal.

Reproduction

1. Compose a message.
2. Attach an image.
3. Schedule it for some point in the future.
4. Submit the message.

Expected behavior

The image message is scheduled to send at the same time or at least a second before the text message.

Platform and versions

Arch Linux
Firefox 148
Sable version 1.8.0
Synapse 1.149.0

Additional context

No response