[Bug] Thumbnail for subscribed playlists broken

[ManiMatter]

When you subscribe to a youtube playlist, the thumbnail under "saved playlists" is gray.

Steps to reproduce:

1. Look for any playlist, I searched for "Carolyn Giran"
2. Open the playlist section, where you see the different thumbnails for each playlist
3. Open a given playlist
4. Subscribe to it
5. Look at your subscribed playlists - you'll see the thumbnail is gray

Example:
I want to subscribe to the playlist at the very right:

This is how it looks under my subscribed playlists:

[unixfox]

Can you reproduce the same issue on other invidious instances?

https://instances.invidious.io

[ManiMatter]

Just changed to another indivious instance and the same bug occurs.

Btw - why do I get signed-out when changing instance?

[unixfox]

Can you post the playlist id?

[ManiMatter]

Any of these: https://www.youtube.com/@CarolineGirvan/playlists

Example: https://www.youtube.com/watch?v=SCxNnWW2zB8&list=PLhu1QCKrfgPWmStsg7imo5EQ0zmkxymJ2
Believe PLhu1QCKrfgPWmStsg7imo5EQ0zmkxymJ2 is the listID?

[iBicha]

Since saved playlists will pretty much always have a thumbnail of its first video, should the DB save the thumbnail to the first video as well? Even if the thumbnail changes later (by changing the first video) at least listing user Playlists will not return playlists missing thumbnails.

[oktayacikalin]

Since saved playlists will pretty much always have a thumbnail of its first video, should the DB save the thumbnail to the first video as well? Even if the thumbnail changes later (by changing the first video) at least listing user Playlists will not return playlists missing thumbnails.

You cannot just take the first video, grab or generate the thumbnail and use it for the playlist? At least, that's what I would think is the correct way.
If the playlist is empty, then I would expect the "broken" image.