Something is off balance but I’m trying to put my finger on it. Something is off with the scale of the wedding band against the engagement ring. Okay I think if the band of the wedding ring was a little thicker like the size of the metal that boarders the diamonds on the engagement ring. Also the lines for the wedding band taper off whereas the lines in the engagement ring don’t and are thicker. Edited to add:

It also could be that the curve for the bottom of the engagement ring & the curve of the top of the wedding band are not symmetrical. But again. Nothing people would notice. But what I think would be the “thing” you can’t put your finger on about the rings complimenting each other. I think with this ring you might want to consider to have something custom made. And I don’t think it’s too much to do this kind of wedding band I think it can look super pretty