This has been an issue for a long time. I’ve been trying to avoid Chromium based browsers, but Firefox seems to be unable to print a lot of web pages without cutting off the content between pages. This is Firefox specific, as it doesn’t happen with Chromium browsers. It’s really a pain in the ass when I need to print something I have to open another browser and print it from there. I see tons of complaints about this online going back for years. I just spent the past two hours trying (unsuccessfully) to print a recipe correctly. I eventually gave up, opened Edge and printed from there. The current state of web browsers is dogshit. It’s either give up all of your privacy or use broken stuff. Neither is good.
Or just print screen right? Joking, but you could just save txt document then. Doesnt help if you care about formating and if you have content that is not just a text.
I had the same problem as OP together with ignoring grayscale settings, but its been a while since last time I tried that