I recently started converting EPUB to PDF with Calibre newest version (v5.7.2), and besides everything run smoothly at first glance, I realized after doing some annotation with Acrobat Reader, that the text isn't formatted correctly in the background. If you double left-click one word, it'll only select partially the word, not the whole. Also, if you copy the whole word and paste it into a text editor, the word will be split up with spaces.
Demo:
https://imgur.com/a/cjHqnFy
On version 4.1 and 4.2 I couldn't reproduce the issue, even with the same conversation settings. I also tried 'Remove unnecessary hyphenation' on 5.7.2 but doesn't make a difference.
Please forgive me if the issue is already known. I tried to find similar posts under this forum, however, I found nothing.
I appreciate any suggestions for solutions from you guys.