Returning from a trip after a few days, booted my pc and installed the updates prior start working. Kernel and nvidia updates, reboot necessary.
After reboot there’s no more second screen. Tried changing from gl-06 to 07, with no sucess.
Discovered this tread that’s probably about this problem with 560 comments.
It looks that the problem was affecting Tumbleweed and now is affecting Leap too.
Is there any fix for this??
It’s a show stopper 
I downgraded the nvidia driver version from 580.159.03-lp160.52.1 to 580.159.03-lp160.49.1 and now I have my second screen again.
Almost certainly as nvidia driver issue than a Kernel issue.
Had to block the package to avoid the update and loose my second screen again.