I had the same experience as I uploaded my game here to itch.io, here's what I did to fix this:
Instead of compressing the game to zip using the one that is IN microsoft, I instead used "7zip File Manager"
then I opened "7zip File manager," highlighted the Game File, pressed right click and I clicked "7zip" then "Add to archive" then a menu pops up, I replaced the option "rar" to "zip" then clicked "ok"
then after that I uploaded the game here in itch.io and it worked.
hope this helps