"Move selected actors to level" not available

I have some actors on sub-level A and want to move them to sub-level B. I have both levels checked-out. I select actors (or a single actor) that is on sub-level A. When I right click on sub-level B the “move selected actors to level” option is not available.
obraz
Both levels have streaming mode set to “always loaded”. What’s wrong?

If the level you want to move to (B in this case) is hidden, it won’t work. You have to unhide level, move, hide.