Video plays only after full load

### Steps to reproduce

Hej!

I have a synapse + apache + livekit personal family server with less then 10 users. Everybody is using Element X. When somebody sends a video to a room, you can see that video only after full downloading. It's OK for pictures, but for video you can wait up to 1 minute. For the record, in the web version, it is quite the same: first, it says that doesn't support, but after minute or two everything plays well.

Apache/2.4.52 (Ubuntu)
matrix-synapse-py3 1.149.1+jammy1

It is asked about my phone further, but it does not reflects to a smartphone, because the same is on Honor (for android) and iPhone 15 Pro (iOS).

### Outcome

#### What did you expect?
Videos begin a playbeck within a short time

#### What happened instead?
Too much time to wait

### Your phone model

Samsung S24U

### Operating system version

android 16

### Application version and app store

Element X 26.03.3 (202603030)

### Homeserver

Synapse 1.149.1+jammy1

### Will you send logs?

No

### Are you willing to provide a PR?

No