Violin Turns Mute?

I was making a score, with a Cello, Timpani and two Violins. However, as soon as I added another instrument, both Violins turned quiet, and even with "fffff" as the dynamic, I could barely hear it. I removed the new instrument, and it stayed this way, until I added two more violins and gave them the notes the previous ones had. However, the same thing happened to those two once I added a new instrument. I don't have any soundfonts on this, and I have no clue if I'm doing something or if it's a glitch.