Gaps between staves

Perhaps someone can help me resolve a misstep I made in Musescore 4. I couldn't find a solution searching the forum.

Attached is the fretless bass part that I created in the score. There is a large gap between the staves (red arrow). I think that I mistakenly hit a key combination that was a command for move staff down, but I can't seem to correct it. Can someone help?

Thank you.