I have Skyrim installed on my computer. I don't want GOG Galaxy to update it. I have all the settings set so that GOG Galaxy is not supposed to update anything without my permission. For every other game this works, but for Skyrim, EVERY TIME I open GOG Galaxy it automatically starts updating it. Why? Is there any way I can straight up HIDE the game from GOG Galaxy?

Question: Why do you use Galaxy if you're not interested in one of the primary reasons for using it?

Because its convenient for other games. Its NOT convenient for games that have tons of mods that break if you update things. And they must know that because they supposedly let you turn it off. But not for Skyrim. The program just doesn't pay attention to its own update settings.

Oh. And it did. Despite me canceling the download it STILL managed to update my game files without permission, and now the mods are broken.

EDIT:
Okay, I seem to have found a sloppy fix. If I delete the files shown in the attached image, GOG Galaxy no longer tries to update the game. It then gives me a nag on the title screen about buying the Anniversary Edition content even though I already have it though.

You might want to consider using the offline installer just for Skyrim. It seems to be basically what you are doing anyway by deleting those files.