QTDragon preview screen not updating

Hi all.

Maybe a bit of a noob question here.

I am running Debian .... Linux cnc-lb 4.19.0-23-rt-amd64 #1 SMP PREEMPT RT Debian 4.19.269-1 (2022-12-20) x86_64 GNU/Linux
With LinuxCNC ....  LINUXCNC - 2.10.0-pre0-370-g5e19eabe7

I have 2 instances of QTDragon setup. On the one that is working when I load a gcode file & zero out G54 the preview lines itself up with the G54 zero.
On another instance when I load the same file the zero point stays at machine zero even after changing (zeroing) G54.
If I cut the file everything works as expected & the colored line is in the correct position separate from the cyan preview.

I would guess this must be some sort of configuration problem but I have no idea where to look.
Any help would be appreciated.
Thanks
 

Are the two instances the same age? There was work done on this very problem not that long ago.

They are both on the same computer. The one that is not working was created from the other using stepconf.

I have since created another instance & that is working so maybe its just something I have done.

It would be interesting to know, though, just to satisfy me curiosity.

Thanks