Sometimes my pdf, prints the all the pages on one page

Please read the following user tip and restate your question/problem in detail: 

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Do you mean each page prints over the one before it or are then all reduced in size and printed on the page, not overlapping. If the latter it could be a corrupt printer setting for muliple pages on one page. Check the printer's Layout settings and make sure they are set to 1 page per page:

If it's set to 1 per page Boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

Note: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will assure a good boot into Safe Mode.

Greetings, jimbohere!

Thanks for reaching out in Apple Support Communities! If we understand correctly, your PDFs are not printing as you would like.

Let's see if this helps: Change Printers & Scanners preferences on Mac. You'd want to make sure the preferences are set correctly. We also want to call attention to the bottom of this guide under "See also". You'll find other resources that might get this working for you to set the printing options.

As a suggestion, you'd also want to look over the Owner's Manual of your printer. They might have a troubleshooting guide that addresses this as well.

All the best.