Timeline cannot scroll up more thana few days, continuously flashes and generates about 1500 errors per second

### Steps to reproduce

1. Scroll up for a while, reach a few days back
2. Top 2-3 lines start flashing, scrolling stops, flash continues
3. firefox emits _a lot_ or warnings about ` Using deprecated camelCase config settingDefaults`

### Outcome

#### What did you expect?
Scroll back as I please

#### What happened instead?
Stopping at top, flashing

### Operating system

Debian/Linux

### Browser information

firefox nightly

### URL for webapp

https://riot.grin.hu/

### Application version

griot version: 1.11.86 Crypto version: Rust SDK 0.7.2 (517d99b), Vodozemac 0.7.0

### Homeserver

grin.hu

### Will you send logs?

Yes

Start by reproducing the issue at https://riot.grin.hu/ with Firefox Nightly, scrolling the timeline upward until it flashes and stops. Check whether the deprecated camelCase settingDefaults warnings correlate with the failure; done means the timeline scrolls farther back without flashing or generating the reported volume of errors.

Written by the indexing model from the issue text.