I made 2 games, Megaventure and Sandbox, that are still showing up in the itch client under my creations even though I deleted them from itch.io.

This also seems to happen with a deleted collection, The Megaventure Collection

This can happen if the app has not synchronized with the remote server yet. Although these items may not display, since they are deleted, they are no longer available to download or access. All you’re seeing is what’s cached locally on your computer.

Synchronization should normally happen automatically or when you bring the app back into focus. You can try pressing F5 to force a refresh.