There is an issue with the asset export options in Adobe illustrator. When exporting with the png scale options .5x, .75x, 1x ,2x, 3x, etc... the file's ppi is also changing rather than staying at 72ppi. For Example when exporting a 100x100 square @1x, 2x, & 3x the expected behavior would be to get 3 pngs (@1x - 100x100px @72ppi), (@2x - 200x200px @72ppi), and (@3x - 300x300px @72ppi) (I'm pretty sure the asset export used to work this way); However what is happening now is you get 3 pngs (@1x - 100x100px @72ppi), (@2x - 200x200px @144ppi), and (@3x - 300x300px @216ppi) (See attached pdf). The easiest way to replicate this is to export a @x scale png, reopen it in AI or PS, or copy and paste the png into AI or PS, or place the png into AI, all the @x scale png will be the same size but different ppi. The work around is to manually scale every asset and then export at 1x, which can be a big hassle when exporting multiple scales or lots of assets. It's odd that the ppi and @x scale asset options do the exact same behavior now.

Windows 10, AI VERSION 25.0.1