Export PDF file Illustrator

[stallen]

Good afternoon. I have a little problem.
I am creating a folder in Illustrator for a client in A4 format.

I exported the first version and it was in high quality.
Right after I moved the images and just inserted some logos. After that, I can't export in high quality anymore. The PDF now only has the images distorted when zooming. This problem only occurred when I changed images of position and inserted some logos. The export process was the same for both.
Attached the image with good quality and after the changes it was with poor quality.

Inside Illustrator it is in good quality, but exports are bad.

Help me please.

[Monika Gause · Accepted solution]

Go through each of the saving options in the PDF dialog and adjust them.

Also: talk toyour printing service about what exactly they need.