I've been having this issue and what worked for me was to click that "I already paid for this" button and request your download links via email. Open the link with the name you want to download and enjoy! Did this right before writing this and still works, so it must be something Itch sided. I hope people see this comment before buying stuff again.
Why are you even here if you don't like the content? Most of your recent comments show you being an ass for no reason. AND bragging about your own gooning choices does not make you the bigger person. Takes one to know one, I guess.