I believe you that the later amendment would win, although that’s not necessarily evident from the example of the 21st amendment, since its text explicitly repe

I believe you that the later amendment would win, although that’s not necessarily evident from the example of the 21st amendment, since its text explicitly repeals the 18th amendment and thus doesn’t leave the ambiguity of two contradictory texts in place. A better example might be the 17th amendment, which changes the way that US senators are elected as described in Article I.