447/5000 Why ionic fully reloads all the project when I modify the scss styles

Hello friends, it’s a few months ago when I changed the styles of my project ionic it just reloaded the page I was working on and then one morning it started to load the whole project after each modification made on my code scss. I would like to know if you can help me understand what had happened on it? And how to make it redervant like it was before?