Thanks. The concrete had a few cracks that were cleaned up with an angle grinder and filled with Sikaflex filler. Then a roofing sublaminant material was laid out and taped before applying the Dricore layer, which was then taped at the seams and the walls. The osb then sits on top and is screwed into the concrete with Tapcons.

The humidity improved with the OSB because the heat during the summer wasn't hitting the cold slab, but I did do some moisture tests and it ranged between 9-14%. So it seemed to be reasonable. Bear in mind the OSB has been exposed for a few years and we don't have central air so there still is high humidity during warm seasons. It was high as 80% some days.

From the DriCore installation instructions:

"Please Note: We do not recommend the installation of a vapour barrier beneath our Subfloor panels as doing so
could lead to trapped moisture."

That roofing sub-laminate may be causing you issues as my first thought was a moisture sandwich which was confirmed if I looked up the correct DriCore product.

The product I'm using is DMX 1. I'm checking to see if it advises against the vapor barrier, but I could see how that might be a problem with a similar material. Thanks for pointing that out.

I would get back down to slab. clean scarify ,reassess /properly treat cracks.

Level slab,( bonded screed or leveler)

then dependent on elevation gain and run and rise concerns of staircase id opt for a thermal break and there are a few options . Bonded foam board(wedi) , schluter makes a ditra heat w thermal break, or at minimum a bonded nobleseal TS prior to tile or any floor covering.

You have a substantial investment ahead of you it should be noted about Cracks...any OUT of plane slab cracks are likely to move. these options ive presented will not fix out of plane movement

Noted, thanks.