Hello fuzio,
in the german forum lesen.net someone suggested a handicraft solution for that problem:
https://www.e-reader-forum.de/ebook-...pcover-bugfix/
Just cut out a piece of metal and stick it into the cover. (He used a cut-out piece of the lid of a glass with salad dressing)
This way you don't have to disable the sleep cover function. (I don't know how to do that).
Good luck.
Klecks.