OK - tried the new posted download -
Installed to the same, but reformatted, memory card to eliminate that variable.
Used software manager from Dietpi to install a desktop and tightVNC - then …
“Poweroff” and restarted with little button. Then “Poweroff”, pulled power plug, reinserted power plugt = all worked as expected!
Tried “Shutdown now” and restarted with the little button and did it again then pulled and reinserted the power plug = all worked as expected!
Appears the shutdown/power off/unplug power problem is solved …
Thanks for the effort.