Nitro 12 (creator?) not printing webpages

[gentPDF 0]

As title says, nitro is not creating/printing from (at least some) webpages. Had to use windows inbuilt pdf print. Machine is admin by me, browser is Firefox, OS is Windows 10, everything up to date, Nitro is set as default printer, etc etc. Not sure how recently the issue began - I would guess within the last month. Pdf of page created just fine using windows default pdf creator. I've read the latest dozen or more thread suggestions, nothing works, including reinstalling the pdf creator (via help menu). I'm a student so I will need to get this squared quickly or i'll just have to use another pdf svc...thanks