This is happening with other image files as well, for example .JPGs (pictures). I'm using Save for Web because my file has cuts for the Instagram carousel.
I tried to generate a PDF from the printout, there is no such cut, it leaves everything on the same "sheet" and the size is disproportionate to the 1080x1080 px as well.
@AkanchhaS8194121
I talked to a colleague and he gave me another way to create a PDF using Photoshop! File > Automate > PDF Presentation, and choose the images and generate the PDF. It solved my problem for now, but I need to see how to solve it later.
Thanks for the help, I really appreciate it!