No artwork in media player and mini-media-player

Hey,
I don’t get any cover photo art work from both cards: media-control and mini-media-player. I also tried both my TV apps or via Xiaomi streamer, and from both sources, it tells the name of the media correctly, but not showing any image.
any idea?

Screencap -18-08-2020 at 12.37.16

did you find a fix for this? I’m having the same issue.

mini-media-player

artwork: material

Here →

 - type: 'custom:mini-media-player'
        entity: media_player.sonos_group
        group: true
        volume_step: 1
        sync_volume: true
        show_group_count: true
        when_paused: true
        artwork: material

cover to display current artwork in the card background, full-cover to display full artwork, material for alternate artwork display with dynamic colors, none to hide artwork, full-cover-fit for full cover without cropping.

It’s plex. I get artwork from my PS4, Google Podcasts, YouTube, Google Movies, etc… Just not plex. It’s not passing the right info it seems