Just updated to Ubuntu 18.10 from 16.04. insync 1.5.5 app window display is too small to read on my 4K, laptop screen. Display Scale set to 200% works for all other apps - changing scale does not seem to effect Insync, though. ??
Other answers I saw to similar questions did not help.
gsettings get org.gnome.desktop.interface scaling-factor
uint32 0
gsettings get org.gnome.desktop.interface text-scaling-factor
1.0