wrong covers displayed when there is no cover available - LMS 7.9.1 on ubuntu 16.04

Hello,

I have a squeezeboxserver 7.9.1 running on an ubuntu 16.04 system.

For those tracks or albums which have covers included as file or mp3-tag, the correct cover-picture is displayed, but the vast part of my tracks do not included covers.

When playing such tracks with no cover, the SBS occationally starts displaying some wrong cover-pictures. Further it seems that the wrong cover stick with the track until I rescan and restart the SBS. Afterwards eighter there is "no cover" - as it should be - or another wrong picture might appear in the same place. Anyway how to fix this or maybe set a default picture?

I would think myself of being quite capable handling issues on my ubuntu system and hacking the squeezeboxserver but tbh, I have no idea where to start with this issue. Any hint or maybe link to some other thread is appreciated!

Thank you,
Norfolk

edit: To be specific, the wrong cover is displayed in the web-interface as well as on the radio or touch, so I'd think the server fetches and delivers the wrong picture.