Thank you for the last 3 replies guys.
It's from the system app Configuration update.
Unfortunately it's not possible to erase the notifications or block them - please see photo above and below:
Yay! It looks like I've solved this at long last!:
- 3 dots top right
- Show system apps
- Configuration update
- A new version of Recommended apps is available*
- Lock screen
- Do not show notifications
* I'd already followed the last 2 steps for Recommended apps but that didn't resolve the issue, at least on its own
I'm pretty annoyed with Samsung for necessitating all this detective work!
When I contacted Samsung support the only resolution they could suggest was to restore factory settings, which would have just given me more issues to resolve!