The Union of the United States existed before the Constitution and continues under it. The United States existed before the Articles of Confederation and Perpetual Union. The Supreme Court of the United States has steadfastly maintained for more than two centuries that the United States began on July 4, 1776 and has continued as the same country ever since. (Madison said July 2, 1776, but the Supreme Court said July 4, 1776).On what legal basis do you determine that Rhode Island was part of the Union in that time period between the implementation of the Constitution and Rhode Island's ratification of it? Can you provide sources to support your view? The facts demonstrate to me that they were in fact not in the Union, but that Congress/the other states gave them time and leeway in the hope that they would ultimately join, but after a number of votes rejecting ratification, finally had enough.
As to the votes: they were deliberate attempts to avoid the instructions to call a convention. When Rhode Island did finally call a convention, that convention did (eventually) ratify the Constitution after meeting in March and May.
Against this, what legal basis can you present? What sources support your view? What fact can you show that says yes, what you want to see actually happened? Can you actually find a document from Rhode Island saying they are leaving the Union? Can you show a document from the United States telling Rhode Island they are out of the Union?