Just gave it another try. This time I erased my kept /home for deepin from an older setup and now it completely worked.
Seems some old settings interfered with the new installation. Thx for the update @eric.
- on login I see the login name from /home instead my full name, while for any other operation I do get the full name offered, but probably it's a security feature
- deepin forgets which monitor is my primary. this issue started with live ISO and is ongoing after installation