This is probably an "as intended" behavior but if you have a screenset with a floating console on a separate monitor and that screenset is "locked", wouldn't you that if for some reason the console became "docked" (mysteriously), you would be able to select that screenset number again and it would return to the state that it was when it was locked?
I understand that it is necessary to be able to change the state of any screenset (locked or not) that you are working on otherwise we would be stuck on one view and we couldn't open another window or so on. But it seems like you could go back to the original state by selecting the same number.
What I have to do to work around this is to go to a different screenset and then back to the locked screenset.