I followed your instructions exactly. I get this error:
insync start --no-daemon
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
QSocketNotifier: Can only be used with threads started with QThread
/usr/lib/insync/insync: symbol lookup error: /lib/x86_64-linux-gnu/libEGL_mesa.so.0: undefined symbol: wl_display_create_queue_with_name