Sorry; did you figure this out? I've never used the itch.io app so I have no idea why it wouldn't work.
its not something that i as a reader can figure out. The itch.io app only streamlines the process with a simple install and launch game button. there have been multiple vns over the years i've seen this with and it has never been a reader issue. Its code within the game itself that the ITCH.io app is clashing with. its rare, but it DOES happen.
every time i've seen this, i've posted it. and 90% of the time the content creator sends out a new update shortly after that fixes the issue itself. I personally don't know how to fix this. and even if i did, this is something that only the game author can fix
(ps. i apologize if this message sounded harsh, I was only trying to give a logical response that may help)