I have an 1890's that someone had glued 1970's shag carpet to oak hardwood floors. Also had a maple hardwood floor in the kitchen with several layers of linoleum glued down with the black adhesive. After trying sanding, adhesive remover, paint stripper and scraping someone told me the solution that does work! It will sound counterintuitive but you mix a strong solution of TSP cleaner in a bucket of hot water. Then mop this solution onto the floor keeping it wet for 40 min or so. The TSP solution will turn the glue to mud which can be easily scraped off. When nothing else worked, this took care of the problem. If you leave the oak flooring wet too long, it can warp, but I used this method in 3 rooms and then was able to sand and finish and they turned out beautiful. The maple floor cleaned up beautifully as well! Attempting to sand the glue mess off the floor will fill up sandpaper sheets almost immediately - the TSP method works!!

I am not an expert at all but it occurred to me that you may have incompatible products on the floor. When you have solvent and wax based products the result is sticky or dull etc. To get it all off I used to use mineral spirits. I worked the 800# for a floor wax for a bit and this is what would happen if someone used a wax and then Murphy's Oil Soap. Before you try this, to see if you have two incompatible products on the floor. Did anyone use Murphys or any paste wax or any other kind of wax?

Most of these OTC polishes (Bona Polish, Weiman, Rejuvenate) are total crap. They scuff easily, wear poorly and don't repel soil. Quite often they're applied over floors that aren't clean and they trap soil and make the floor look dingy. People add coats to make it look better and end up making it much worse. Contact the manufacturer to inquire how to safely remove it from your wood floor. Swiffer Wet Jet is another product to avoid IMO. I've seen it leave a film on the floor. After the polish is removed, contact your floor installer or the manufacturer to see what they recommend.

I see one+ boards that either took more stain or were darker before staining. Two boards to the right of the dark one is a half and half light/dark board. Seems to me the center of the floor is made of darker boards. Not unusual, but not optimum placement. It is sometimes difficult to look at raw wood and tell how stain will be absorbed.