Hardwood floors cupping even after replacement
Solid wood flooring in a wet area is inherently risky due to the moisture everywhere.
Pine flooring (a moisture-absorbent softwood) is inherently risky to install.
Solid boards are inherently more prone to cupping than engineered boards.
Gluing a wood floor to concrete is inherently risky because concrete is a big sponge that absorbs and releases moisture in an unpredictable and uncontrollable manner.
Gluing a wood floor to anything is inherently risky because this install method allows air movement over the top of the wood, but not the bottom, encouraging moisture to congregate there.
Laying anything moisture-sensitive on top of concrete after it's been newly-cast is inherently risky because of how it gives off moisture for a while.
Very wide boards (6" and above) are inherently more risky to install as a floor, as they are inherently more prone to cupping if they were plain or flat sawn. This is especially true of solid wood, but it can affect engineered wood with a thick veneer layer. I recently examined a sample of a 7" wide engineered board with a 4mm oak veneer layer of Chinese origin and noticed it was already ever so slightly cupping. Stay away from the really wide stuff unless you know it's of extremely high quality.
Finally, old "reclaimed" wood is usually marked by imperfections and "character." That's the whole point! It is likely that this wood was not of especially high quality to begin with when it was first installed however many tens or hundreds of years ago. "Rustic" or "Antique" wood is usually not noted for its level of precision or moisture resistance compared to modern materials. Back then, the solution to moisture problems was to make everything as leaky and air-permeable as possible to permit rapid drying. When you seal up an old building with vapor barriers and insulation without solving the underlying moisture problem, it often begins to rot. The same kind of thing seems to be happening here where one face of your boards are totally sealed up but the opposite face is exposed to moisture.


In isolation, a couple of these factors are probably no big deal, but when you combine all of them together, you have a recipe for a high chance of failure. If there is any way to install your floor properly, it would probably be as a nail-down install over a poorly-laid, air-permeable wood subfloor with an open space below it (e.g. solid boards with gaps between them and a basement underneath, not OSB sheeting over concrete), and with appropriate expectations of its quality and dimensional stability.

I would guess that in your slab on grade house, an engineered wood floor made of boards 5" wide or less with an oak veneer top layer installed as a floating floor above a waterproof underlayment would experience no problems whatsoever.