Application Desktop assignment does not last I've got 4 desktops in Mission Control. I've assigned CMD+1,2,3,4 to switch between them.
I've also assigned particular application to particular desktops, eg.Chrome to desktop 2, Atom to desktop 3. iterm2 to desktop 1.
I've done it by opening the apps in the respective desktops and going to Options => assign to this desktop. 

Now I switch a lot between those desktops and I don't know what I do but after half an hour I've usually got Chrome and Atom swapped in terms of desktops. Also, when I check the Options it says that apparently Chrome is now assigned to Desktop 3 (as opposed to desktop 2). 

I know it might be hard to trouble shoot but what am I clicking to reassign them? Any suggestions?
Is there any way to really lock the assignments. 

I rely a lot on keyboard and the idea of 4 desktops/workspaces and switching between them like that has always worked for me. I'm new to mac os so I was glad to find that I can do it here as well. The problem is that I do something to reassign them and have no idea what...
Make sure
System Prefs > Mission Control > Automatically rearrange Spaces based on most recent use
is off



You can then reassign them back to what you wanted by invoking Mission Control &amp; dragging the thumbnails at the top of your screen back into the correct order.