Got a real mess there.
Most likely it was not prepped right and there's not the proper support under the steps.
It also never should have been installed that close to the rim joist for the deck!
If it was mine I'd be ripping the whole thing out and replacing.
Looking to go cheap and it may or not work, pry it up and add #57 under it.
Build nice new wood stairs, bolted to the porch, with some washers as spacers so the gap between can breathe.
But first, prop up that sagging porch.
The whole thing sags like an old swayback mule, put some stacked patio blocks or deck blocks on a patio block down under it, dug down onto firmer soil.
Jack it up for a few weeks or months until it returns to a decent level besides sag city.
Then bang in some 4 x 4 pieces to replace the jacks.
Thank you! The siding is missing due to termite inspection, hasn’t been replaced yet so hoping to address steps while it’s gone...
Home was built in 1901...not sure how that may affect placing of items such as these steps