Scroll position of main timeline is reset when opening thread

### Steps to reproduce

1. Jump back in the room history catching up on messages
1. Open a thread you stumble upon while catching up
1. Main timeline scroll position is jumped to the bottom (showing latest messages) ❌

### Outcome

#### What did you expect?

The main timeline should maintain whatever scroll I was at before opening the thread

#### What happened instead?

The main timeline scroll position is jumped to the bottom (showing latest messages) ❌

### Operating system

Windows 10

### Browser information

Chrome Version 109.0.5414.120

### URL for webapp

https://develop.element.io/

### Application version

Element version: 50f2b532e907-react-4c1e4f5127bd-js-4f918f684e9d Olm version: 3.2.12

### Homeserver

matrix.org

### Will you send logs?

Yes, https://github.com/matrix-org/element-web-rageshakes/issues/19796