Videos sent via WhatsApp bot don't show thumbnails.

[imding]

Hi, I set up Synapse v1.64.0 and mautrix/whatsapp v0.6.0 with Kubernetes and after inspecting the logs, I noticed that the thumbnail_info field isn't sent by the WhatsApp bot with the m.video event (link), which results in videos having blank thumbnails in the Element app.

Video attachments that do not go through the bot show thumbnails just fine.

[kinduff]

Would love to contribute but I don't know where to start, can you point me to the right direction?