Odroid N2+ Blocky Mouse/Cursor response

I have been trying out PianoTeq on an Odroid N2+ and am getting some strange behavior. So was just wondering if anyone else has had something similar before.

After following some other pages on the forum I've managed to get PianoTeq 6.7.3 up & running on the Odroid N2+. I can get it playing notes from the MIDI keyboard but am getting a strange issue with mouse control.

If I drag the main window around the screen that moves smoothly just as expected.
When I've got the Options window open, if I drag that it jumps in blocky steps of around 100 pixels.

If I try to click on any part of the main window it has very limited response.
When I click on the virtual keyboard only a handful of notes work, is probably 1 in 20 keys.
This  issue is particularly tricky on the Options window, as hardly anything can be selected.
I cant even close the Options window as the X doesn't work.

This oddity does not seem to happen when I use PianoTeq 6.4.1 and I didn't notice this behavior when I was testing out Pianoteq on a Rasperberry Pi3.

The Odroid N2+ currently has:
    Ubuntu 20.04.1 LTS (GNU/Linux 4.9.230-96 aarch64)
    Pianoteq 6.7.3

Cheers,

Mark