When I have sudden bugs with Globals, either with references suddenly being lost, a Global disappearing from the list or even, but very few times, the same var appearing twice, I know it's because a duplicate appeared inside the file.
Make a backup and delete the last var of the name that generates an issue, usually it's the "evil twin" that's lower in the list. At worse, a few references might need to be redefined manually in some FSMs because they might forget about the Global variable.
I wish the Global variables system were more stable too. Several extensions on the Asset Store make use of it so it should be made very reliable to users.
