I've done some more work on this....
Not a fix, but a workaround
Went to Toshiba/Dynadock downloads for Toshiba drivers for PA3927A-1PRP
https://support.dynabook.com/support...ext=1200014770
Latest driver there is 8.2 dated June 2017
Unplugged Dynadock
Removed current driver 9.3 M1
Reboot
Install Toshiba/Dynadock ver 8.2 driver
Connect Dynadock
Works and stable !!!!
But .....
Windows update updated the driver to 9.2
and issues returned
Removed 9.2 driver
Re-Installed Toshiba/Dynadock 8.2
Now stable again
So then prevented Windows driver updates :
Control Panel.
System and Security.
Click System.
Click Advanced system settings from the left sidebar.
Select the Hardware tab.
Press the Device Installation Settings button.
Choose No, and then press the Save Changes button.
So now driver 8.2 is locked in and stable
Not a fix, but a workaround with a driver almost 3 years old
I believe this clearly demonstrates a driver issue
Toshiba / Dynadock / Displaylink
Please investigate why drivers later than 8.2 are failing
UPDATE:
Now stable 10 days with Toshiba driver version 8.2
Compared to previously crashing multiple times a day
Toshiba / Dynadock / Displaylink please respond