I believe our situation was similar. We have a concrete porch at the front door which has a foundation projecting about 6 feet into the lawn. Then a concrete step down to the sidewalk. The step and first section of the sidewalk were settling. I believe this is a consequence of backfill from construction. I had a concrete jacking company lift it. They drilled a hole through both the step and sidewalk section. Then, under high pressure pumped concrete into the void below thus lifting everything level. It cost $275 but I'm not sure I would have been able to lift and level it myself. Aside from a newer concrete "spot" on the surface one would never know anything was done.

I don't like this idea. Build a new step and riser with return ends out of plywood with solid wood overhanging edging glued on. Scribe the riser to the floor so it doesn't rock, and secure it to the existing tread with construction adhesive or silicone. This will look much better and never delaminate, especially after you paint it with the epoxy.

Cement tile would be perfect here. cement tile is 3/4" or more, thick. by the time you put your mortar base and the tile, you should be up by 1" or so. this company is in Dallas, but there are others in Florida and AZ,,,otherwise you'll have to get them shipped. these guys are the cheapest I've found for cement tiles. $4 a tile (8x8) https://www.instagram.com/riadtile/ the black and white ones would be perfect next to the wood. if you have any move the wood, do the cement sides in those. https://www.riadtile.com/product/estrella-tile/

@GreenDesigns This house had gone through a remodel with a previous owner (who in my opinion always went with the cheapest possible solution, and also didn't seem to think things through too much). I can post some pictures and describe the whole house, but let's just say unless we're gonna rebuild the whole thing, we have have to kind of live within certain limitations. The original house is on the higher foundation, when they added this huge room / extension they didn't keep it at level. Currently the big room has two smaller rooms attached that are now at least at the same level as the large room itself (we raised the floor on that one). Before there was an additional 7 inch step down into one of the smaller rooms. For both of the smaller adjoining rooms, the ceiling height is at a lower limit, so we can't raise the floor anymore to keep everything else level. I may post a few more images so you can see what I'm talking about.