In earlier versions of Notes, if you click on the location selection in the bottom right corner of Notes you were able to select the location that is already in use. This is very useful in cases where you may have switched ID files and by reselecting the location it switches back to the ID file specified in the location document. To see how this works, you can still do this from the administrator client or running Notes in Basic mode.
In version 10 (and since version 8) if you click on the location selection in the bottom right corner of Notes, the location currently in use cannot be selected. This forces switching to another location and then back to the one you want. That is a real problem when you only have one location. The only alternative for the user is to close Notes and restart it.
This was probably done when the developer thought there was no use for selecting the location already active. Bad assumption. This is a bug.