Hey WalleP,
I fixed this issue somehow, though quite some time ago. I believe I changed the jpeg quality
“add_filter( ‘jpeg_quality’, create_function( ”, ‘return 100;’ ) );” to
“add_filter( ‘jpeg_quality’, create_function( ”, ‘return 80;’ ) );”.
Not sure though, but worth a try if you haven’t tried it yet.
Cheers, hope you’ll fix it.