When I change the time signature, all breaks I've added to the score are removed

Hi all...

I'm using MuseScore for choral music, so I try to arrange the breaks between bars the same as in the original music (I'm copying from printed music so I can generate MIDIs for helping learn my part).

When I change the time signature, all the breaks I've added disappear. Is this the way it's SUPPOSED to work? It would be nice if it left the breaks in place, at the measure number they were, whatever the time signature.

• Tim