On start up the Itch app does not prevent the Mac from going to sleep. However once I run anything from the Itch app, the app then prevents the Mac from sleeping. I am running Sequoia 15.6.1 (24G90) on a Mac Mini M4.

contact apple

complete it and than final contact itch.io

Not an Apple bug. Individual apps can request that the OS not sleep while they're performing a specific task. Usually this is a game running in full screen, or an app that plays video. Somehow the Itch app is incorrectly setting that flag after a game is run.

Should be fixed in the next version with this patch: https://github.com/itchio/itch/commit/1321ebc88843363346a7ffc44f011c9e3ee34691