Just upgraded via Media Tool HP Envy, decided not to wait for Windows update to offer 1903
Took several reboots to get things settled down.
Avast first reboot came up with both Behavior Shield and Ransom Shield NOT Enabled.
A couple of reboots resolved that, however then Core Shields showing needing to be Installed. Another reboot resolved that and all seems good now.

Going to Upgrade HP Compaq now. Expecting the same rebooting to settle things down.