[RM2K3] INCREDIBLY STRETCHED WINDOW SKINS

I started a new project for a game jam, and was faced with the problem of my custom window skin (system menu graphic) being incredibly stretched out. I was sure there was a simple solution to this, because my first project doesn't have this problem... Except that I completely forgot the basics, because I started that first project in 2019.
I scavenged the internet, but couldn't find a solution. The forums were talking about similar issue in MV, but 2k3 is very different. I'm kind of stumped.

How it looks in a newly opened project:
https://ibb.co/jyvYbFL
How it looks in my first game:
https://ibb.co/Lns5wGb

I found it, now I feel stupid. My brain didn't process that tiny window that pops up at all.
Thank you.