PDF export with pixelated images

Unfortunately, I don't know what to do. Please do not be surprised, I do not speak English and will have this translated with Google. I had Corel X6 and that was enough for my needs. I very rarely need it for trifles. Now I've bought a new PC and unfortunately I can't reinstall it anymore. Since I didn't have a CD. Unlock code is still available. I bought the Corel Draw Graphics Suite Special Edition 2021. 

Unfortunately I can not create a pdf with this version that qualitatively corresponds to what I had before. I tried all the settings. But the inserted images are pixelated in the PDF, not in the original. Can I not create a reasonable PDF in this version? 

If I open the same file in X6 and export it as PDF, this is not the case.

If I do, what can I do?

Thank you for your help