Page Content URL links

I'm new to my job and Squarespace. We have a lot of links on our website and I needed to update all 2022 health plans to 2023. So I made a new section, 2023, and copied over all the text and links from 2022. Then I updated all the links with the new PDFs I uploaded in the 2023 section. So why are all the 2022 links gone and updated to the 2023 ones when I didn't touch that section? What did I do?

Also, could it have something to do with the Unlinked Pages? The 2022 seems to have all the 2023 when I click on the Not linked section that is in the URL slug section of settings for this page. 

Are you sure the link to 2022 and 2023 is the same? If they are different you will get a 404 error.
When replacing a file, I usually rename the new file to be the same as the uploaded file, then delete the file on the web and upload the new file, so the old links won't have problems.

Thanks for your reply! The links are all different names but I'm guessing the problem originated from the URL slug being the same. I didn't touch the URL slug so am confused but when I get a chance I will try to test things a little more. For now, all the 2022 PDFs are gone and replaced by the new 2023 PDFs that were uploaded and linked. The URL slug for 2023 is the same for 2022. 

You mean 4 links in screenshot? Can you share link to page in screenshot?