Clicking the button to go to first unread caused recent history to disappear from the timeline

### Steps to reproduce

1. Click on the button to go to the first unread message.

(removed)

2. Observe that it's no longer possible to scroll down to more recent messages. The message posted by Matthew multiple days ago now _appears_ to be the most recent.

(removed)

### Outcome

#### What did you expect?

Having clicked to see the first unread, I expected the timeline to move to display the first unread. But having done that, I expected to be able to scroll downwards again to return to the most recent message.

#### What happened instead?

The recent messages appear to have all vanished. Scrolling up and down doesn't make them reappear. Clicking away from the room and back doesn't make them reappear.

Refreshing the browser tab _does_ make the recent messages reappear.

### Operating system

Windows

### Browser information

Chrome Version 143.0.7499.170

### URL for webapp

https://develop.element.io/

### Application version

Element version: 4bd1d4144f56-js-43f3e10f05c8 Crypto version: Rust SDK 0.16.0 (8471012), Vodozemac 0.9.0

### Homeserver

element.io

### Will you send logs?

Yes