AFAIK (and I can be wrong), the resolution (dpi) of the two files cannot be the same / the size (width / height) have to be the same.
take your orginal file and:
set the @2x image to 144dpi
set the “@1x” image to 72dpi
Both images have the same x, y values.
Replace the current image by these new ones and run.
When you know, it is not really easy to explain these things. And once you know… things are not easy to explain too, so one can share bad / wrong / not completely true… explanaton. :(
The problem (to understand) lies in the fact Photoshop (by example, but not only) propose by default to “display all pixels” even if the Pixels are <> from Points: the image appears two (or more) times larger than the “display points” settings. Note that I do not have used Photoshop since… ages, so the names can be different.
About 72 and 96 dpi: these are the default resolution (in dpi) for each OS (72: macOS; 96: Windows).
When ou open a 96dpi image in Preview, make a copy / newand compare the results: one image will be "larger" than the other. With Copy / Paste / New, Preview does not always know / support/ respect the original resolution (72 /96 / 144…).
Another simple test you can do is on macOS: take a non 72 dpi image , open a window, open the “Show the presentation options” (translated from French, so the english sentence can be a bit different), click in the Image --> Background and drop that image into the graphic area.
The Finder will display the image accordingly to its dpi: smaller or larger of the standard size (72 dpi) depending on its real dpi value.