[AchillesPunks]

Could somebody please help me out?
Thank you.

You need to update skin helper service, skin widgets, metadata... Update it from the GitHub. This was fixed long time ago.

Their official GitHub pages or some fork?
One would think that the newest ones would be on Kodi repositories.
Thank you.

I've already posted the link above. That link is the only available repo for Kodi Matrix.