Renovating a basement and hired company (contractor #10 to stain concrete a terra-cotta color. Majority of concrete was previously covered in carpet. An adjacent landing had tile. Company proceeded as follows:
1) grind floor (using 40,80, 100 grit metal blades to remove glue/prep floor);
2) Continue grinding using diamond bass beginning at 100, 200, 400 grit.;
3) Stain floor using Scofield faded chemstain classic faded terra cotta (http://www.scofield.com/concretestain_main.html)
4) densify floor after stain (to seal in fill in concrete pours) using formula one lithium identifier (http://www.scofield.com/lithium-densifier.html)
5) continue girding with 800 grit (for a low sheen/matte finish);
6) seal with two coats of concrete sealer (http://m.prosoco.com/Product/bff6fcf0-50bc-44b6-ac42-0a1c707e5526)

At completion, the main floor looked great but the transition between the main floor and adjacent landing looked very different. Contractor #1 advised us to bring in a specialist to resolve the color contrast.

Contractor #2 recommended a "3 step cleaning process. I would like to go in with a material matched in color to the rest of the existing floor and trowel over top of the lighter areas. It will still require a stain to get the depth of color. Then 2 coats of sealer in the new area and 1 coat of sealer on the entire floor to create a consistent sheen across the floor surface." She sealed it with Semco Crystal coat. Contractor #2 dramatically improved the transition between landing and main floor. But after she sealed all floors, there was a dusty residue covering the main floor. On Contractor 2's recommendation, we tried to water mop the floor to get rid of the dust. Even after water mopping the floor looked like it had residue on it and the color was coming up. In some areas it was gritty to the touch. It also looks very "brush strokey"

Contractor #2 hypothesized that Contractor 1 did not neutralize the stain and that is causing the stain to *eat through the sealant.* Contractor #1 claims they neutralized the stain by washing it 2x with baking soda and adding a neutral cleaner (day con) to the mop water as they mopped the floor. This would have been step *3a*. This step nor products were written out in contractor #1 quote. Contractor 2 ordered a Hydrion PH pencil test which is reading 9-10.

Can anyone offer any advice on where to go from here:
1) Is it possible the original stain was not adequately neutralized if at all?
2) Is it possible that the wax sealant applied by contractor 2 caused this reaction?

Where do we go from here to stablize floor so we can complete the project? All advice will be greatly appreciated. Happy to fill in any details.

Image shows before and after shots plus streaky dust.