I have two games on my account, both hidden. One of them is in the prototype state and the other one has limited access. The older one (the prototype one) loads just fine when I try to run it through the Itch app, but no matter what I try for the newer one (that uses the exact same tech, just vanilla HTML+JS+CSS) fails to load. If I press Shift+F12 to debug it, it shows me the standard about:blank markup, as well as showing an error 404 in the JS console for some itch-cave://game.itch/[…]/inject-game.bundle.js.map (URL shortened). Both games are uploaded as a ZIP file, with the game’s entry point in index.html, but as soon as I did that with the newer game (before, it was one big bare HTML file which worked) it broke and doesn’t even reach my code.
Reuploading doesn’t seem to help. The issue does not appear when opening the game’s Itch page in Firefox or Chromium and clicking “start” on the embed.

I just continued developing the game and uploaded a new release, now it suddenly works? No clue what that was, but I have checked that the Itch app didn’t even load my game’s resources before, meaning my game’s code itself could not have been the problem. Maybe the problem was resolved by me restarting my computer several times because of a separate, unrelated problem? At least it works now…