@jlrumeau
It's a bit late but you look and read Graphical Interface Version 4 in our documentation before you decided to change the display mode?
docs.masso.com.au
From information note.
The Vertical interface is primarily designed for MASSO touch
The only way to get back to vertical mode is to attach keyboard to the USB port and get back into general settings and return to vertical mode.
Regards,
Arie.