wrong permalink in index page

today i moved 4 old posts to the trash (about two months old posts) and then created 4 posts with the same name. When I tried in them in the index page I noticed that the permalinks for those posts end with -2 (ex: …/test-post-2)

I thought this is because I didn’t remove old posts from the trash and I moved current ones to the trash as well (so 8 posts in total in the trash). Then I deleted everything in the trash and created the posts (with same name again)

Still the index page shows permalinks ending with -2 but when I click I get 404 because actual pages do not have permalink ending with -2.

All these posts are under one category and when I view the category archive page it shows the correct permalinks and directs to the correct post when clicked on the link

When I click on a post from the post editing windows it also shows the permalink without -2. Additionally I am not using any caching plugin

Wonder what I am doing wrong here.