It’s reality. I’ve provided the resolutions the states passed when they ratified the US Constitution showing it to be the case. You’ve provided no evidence to refute it.
The evidence is really self-evident - if these signing statements had any force of law they would have availed themselves of it. None of the rebelling states pointed to these statements and declared this so-called right. None.
And that is because even the slavers knew that there is no “right of secession” - especially not a unilateral right. The only way out of the union is through mutual accord of ALL the states or by revolution and the force of arms.