b0o0d

Thanks for the quick replies.

I’ve found the problem & solution.
As always it was an unfortunate plugin interference.

The “disable blogging”-plugin has a setting which can (as you might have guessed) disable “blogging”. Not only does this block posting, it apparently also silently sets the show_on_front setting to “page” every time the dashboard gets loaded.

And this setting was somehow triggered by the upgrade.
(By the way, I use the plugin for its commenting disabling functionality.;)

Thanks!