Read and unread notifications get mixed up

Steps to reproduce

1. Get a notification and mark it as read
2. Get another notification
3. Go to notification page
4. Toggle 'Show read notifications' switch a couple of times

What happens?

Read notifications are mixed with unread notifications after few clicks and read notifications are empty.

What is expected?

Read notifications should not move to the unread section

Context

Funkwhale version(s) affected: develop