I was told by my supplier that the manufacturer they deal with said they were sourcing from somewhere else.
"This item was not reformulated; however, we were having issues with cold weather so we are now purchasing the product from a new source."
What cold weather means, I don't know, but this is all of the scoop I have on it.
Perhaps your tubes froze somewhere in the supply chain? Is that what it would do if it froze? I have no idea.