Ok, I fixed it...
In Armory Crate, go to the top left option "Device" (Looks like icon of mouse and keyboard).
Then go to "Addressable Headers" tab on the top.
There you will see Strip options with Number of LEDs. Both mine were set at 120.
So, I changed the number of LEDs to 60 on the header I was using, and it started working again. I then changed it back to 120, it applied the setting, and it still works normally.
So whatever this did reset things to work again even though the setting isn't changed at all. Hope that helps someone.