Inputting a note adds extra beats to a measure

In the past, when I had for example two eighth notes, and I replaced the first one with a quarter note, the second eighth note would disappear. Now when I select the first eighth note and input a quarter note, the measure becomes one quarter note longer. For example 3 beats becomes 4 beats. See measure 10 in my example, I wanted to replace the eighth note rest and the following eighth note with a quarter note, instead an extra beat was added.