Mixed notes in a chord

Hello everyone,

I am entering a song into Musescore so I can do some re-arraignment for a performance. This is for playing on a keyboard (Piano) which is what I selected. The music is in "C" time.

On the original score, several times the first chord in a measure has a half-note as the top note, with a quarter note under it. The next beat is a quarter note, followed by 4 1/8 notes for the top note and quarter notes on the 3rd and 4th beat.

However, I can't reproduce this in Musescore. When I enter a quarter note as the second note on the first beat, the top note is changed to a quarter note as well, which is incorrect to the original sheet music.

Is this normal behavior for Musescore? Is there a workaround? Thanks!