PDF objects suddenly loose quality after cropping in Adobe Illustrator and get pixelated
I routinely placed and cropped PDF objects within Illustrator, without any issue. From today, when I crop a placed PDF, it gets kind of pixelated after cropping (example below). This never happened before. The quality loss is also observable after exporting the project.
I already removed and re-installed Illustrator, but this didn't help.
Can you please advice how I can fix this?

