As I said above: "In other cases (NC, TN, AL, FL) it was the constitutional action of the whole state; in the case of West Virginia it was the unconstitutional action of a piece of a state which had no authority over dissenting counties."
But I forget. You don't understand the Constitution.
Actually I do, apparently better than most Lost Causers.
In the first place, your claim of a 'constitutional action of the whole state' is wrong. The Southern acts of secession were not legal, as the Supreme Court ruled in 1869.
And there was nothing illegal or unconstitutional about the creation of West Virginia. A single state may split itself into two or more states with the approval of Congress and the state legislature. The partition was approved by a body calling itself the loyal Virginia legislature and which was recognized by Congress as the only legitimate Virginia legislature sitting. Congress later approved their actions, and the Supreme Court recognized the legality of the split when they heard the case of Virginia v. West Virginia following the rebellion. The case which, by the way, said West Virginia could keep the counties in question.