music drops in volume but there are no dynamics

I cannot figure out why the music is fading out at a certain point. I want to check the mixer, but nothing happens when I click it. (I get that in other projects too since I started using MuseScore 4). Listening again, I think it isn't a smooth fadeout. It suddenly drops in level at m.59 and then drops again to a very low level at 61 and then comes back on at forte in m.70.