JPG to PDF then adding a page doesn't work

I'm trying to convert jpg files of stylized text and art to PDF. Had no problem with this on the first few. Now, PDF (Pro version 17.0 on Windows 11) is creating large blocks of black over parts of the text, which can't be removed. No idea why. I also have Photoshop Elements v. 20.0, and have tried saving the images there first, either as jpg or as PS PDF. Same results. The error message says I'm not allowed to try and edit the PDF by trying to add a second page because I'm working in Adobe Express, but I can do this in Adobe Acrobat. However, I *am* working in Acrobat, which I've verified multiple times. Extremely frustrating.