problems with converting pages to posts

Hi, I am converting my pages to posts with p2p. Seem to work good but when I convert a page to a post the url changes from https://mysite.com/articles/pagename to https://mystie.com/articles/http:/mysite.com/articles/pagename

Not sure why it is changing to this new directory. Any suggestions?
My site is https://www.freeshedsplans.com
You can go to the front page then click on the only post(Homeowner’s Guide To Shed Building) which is the same page you are on, the front page, but if you click the post the url changes, and it does this when I convert pages to posts, which I want to make all my recent articles go under posts, not pages, but when the url changes for my articles the search engines will get 404’s, make sense??

Please excuse my confusion, any help would be appreciated.