Previous Title Button missing html tag title

Steps to reproduce

1. Play any track
2. Hover over the player controls

What happens?

Previous Title-button has no hover title

What is expected?

That it does...

Context

Funkwhale version: 0.21.1 - Mono-Container Docker setup

Skimmed through HTML source of my instance and found this:

The highlighted tag should have a title of "Previous track"