For one thing, I don't agree with the calculator recommendation of a 40 band, and I think you need a larger band and a smaller cup volume. The reason this band feels fine is because that two extra inches of cup room on either side is substituting for band room that you need; meanwhile the cups are enormous.

I'd suggest a different bra in a 42 band, corresponding to your loose measurement of 42". I'd recommend the Elomi Morgan in 42H to start. I see it was recommended to you already in 40HH, but I strongly suspect that once you go down a couple of volumes in the cup and also in a bra that has narrower wires, you'll get too much distortion in the wires when you close the band, and lose cup depth.

This 42H would have a larger cup volume than your 42H in Cacique, because it's UK sizing. In Cacique sizing, 42H would be the equivalent of 42G UK.

Morgan is a full-coverage bra, but not so high cut as Goddess Alice, plus these cups hopefully will fit or at least be closer to fitting.

I suspect you may have to try a few things before you get your best fit, but if you do try this one, fingers crossed that it works.