Brush tool acting strange

Hi there

I've recently had this problem where my Brush tool is not making a smooth line but instead it's making these odd corners every time I draw with it. Before that I didn't have this issue because I was already using the Brush tool in the same document but it appeared like normal. Now all of a sudden it's not working right.

But whenever i open up a new document and use the Brush tool there, it appears like it normally should. I think it's something about my settings that's different but i can't seem to find anything odd in my settings.

Any help is appreciated! Thanks!