spacing issues - need help!

Hello - I'm not new to notation software, but new to Notion. I'm wondering if there is a way to stop the staff spacing from changing when I add dynamics into a measure. It's resulting in many of my lines being spaced differently and I'm frustrated by that. Is there a way to "lock" staff spacing? I've set it to 3 in the score settings but once I add dynamic markings it bumps bigger every time and seems to ignore the setting I just put in. Thank you so much for your help!