I swapped out spigot to paper for better performance, but the server wont even start 
Both are 1.19 version and world was generated in 1.19
Both are 1.19 version and world was generated in 1.19
16.06 05:54:42 [Server] INFO This server is running Paper version git-Paper-366 (MC: 1.18.2) (Implementing API version 1.18.2-R0.1-SNAPSHOT) (Git: b1ac25f)
weird, i selected paper 1.19 on shockbytewell that log shows that you ran the server with 1.18.2. And you can't go backwards in versions. So try running the server with actual 1.19 paper.
could be ye, there also seems to be an option for custom one, so maybe i can try insert it myselfMaybe you should bring this up with the support of your host then, clearly they are serving you the wrong jar.