I would try the nightly-build or bleeding build as mentioned. You can also use moserial (GUI serial terminal) (
wiki.gnome.org/action/show/Apps/Moserial...ow&redirect=moserial
) to test serial connection. Connect with 115200 Baud 8N1 and send "MountInfo#". The mount should return with its 4 digit model number. GEM45 -> "0043" GEM45EC -> "0044".