try it now
Same issue
Corkus its in your library. Click the drop down arrow at the top right of Itch.io (located next to your name) and select Library.
That's exactly how I got to that page, it is in my library however it stops me from downloading the latest version without paying again.
I don't have this issue with any other game I have purchased on this website regardless of how many new updates come out.
did you buy the game during a sale?if so did you buy it for 10$?
I brought it on sale, then later brought it at full price, then again brought it at full price because it wouldn't let me download the latest update without repurchasing for full price