I’m using PowerPress 8.6.2 on WordPress 5.7.1. I used the import function within the “Get Started” menu option under PowerPress.
Just to clarify again, the https:// was added to the guid AFTER I updated an imported post entry. I had initially thought it was the import process, however that was my mistake. I had initially completed an import and before checking the guid’s I made some updates to a bunch of the post entries which then updated the guid’s incorrectly. The imported entries I didn’t touch had the correct guids.
Sorry for any confusion.