I don't have any Insider Preview Windows installed to test. I assumed this from name, because there were many UUP-CTv2 builds that were quickly pulled down.
I can only find one publication about it, and it's based on a reddit poster leope. It's mentioned in the announcement: - Small app update: Thanks everyone who reached out about the grid alignment issue in the Calculator – this has been fixed with the 1812 version of the app. You probably have to be a very active insider to get the updated calculator. My IP VM's contain the same calculator version as you do.