I was gifted KSP, installed and played for awhile then took a break for a month, upon going to launch it yesterday it was not authorized so I tried to verify/etc and still not authorized. So I thought I should try to uninstall/reinstall which removed it from my library.

In my order history it shows that it was added to my library and it was gifted but yet I have to buy it now? I submitted a ticket but have yet to receive a response so while I'm waiting on that I thought I could come here to see if this has been an issue before.

TL;DR: Gifted KSP, played for a bit then took break, now it's removed from library and it wants me to buy it now.

Have you tried an account refresh? Also check with a browser if it shows up in your library on the website.