How do you unmute an electric guitar?

When you put "mute" over the electric guitar's measure, it changes the sound of the guitar to be muted. However, putting "open" over a later measure does not undo this. I'm almost completely unfamiliar with the more complex semantics of editing sounds in musescore, so if anyone can give me any ideas or step by step instructions for what to try to resolve this, it would be much appreciated.