Seem to be related to this; https://bugs.launchpad.net/ubuntu/+source/plasma-desktop/+bug/1920596
Managed to get it working above 300dpi using the official SANE PPA https://launchpad.net/%7Esane-project/+archive/ubuntu/sane-release
Seem to be related to this; https:/ /bugs.launchpad .net/ubuntu/ +source/ plasma- desktop/ +bug/1920596
Managed to get it working above 300dpi using the official SANE PPA https:/ /launchpad. net/%7Esane- project/ +archive/ ubuntu/ sane-release