OK folks. This should work.
This worked for me:
I deactivated all my plugins and then reactivated them again and it now works perfectly.
It may even be enough to deactivate and reactivate the sidebar login plugin only, but I already tried all of them.
I suspect a conflict with other plugins may be the cause or just needs resetting after certain reorganization of the WP core.
Anyway, it workd for me. Try it.
ATB
