Here’s a few of the games that are affected: 127001526408720, 12561389610, 124798709814661
Expected behavior
I expect assets to not be shown when using the GameThumbnail rbxthumb type with a game id, GameThumbnails require the root place id instead of the game id unlike GameIcons leading to this common misunderstanding.
This is a Roblox game I created, my current solution is using the start place id of the game, either the documentation should be updated to denote this discrepancy or using the game id should return the intended result.