I didn't get time to reboot in safe mode last night, but I did turn off all rocker images.
With regard to the GUI, I normally always have this open in a tab and never seen out if control resource usage. I did fairly recently update the OS - maybe two weeks ago.
This morning, Parity has competed without error and the system is still stable.with low resource usage and the state is still stable. I guess I could try turning each docker app on, doing 1 a day, to see if I can narrow the issue down.
It will take a while to complete this as I have around 20 applications I will need to restart.
Thanks Jorge for your help.