I had to roll back to 25.7 because export scaling at 3x looks horrendous in all later version. Here are my export settings and what it looks like in 26.2 comparted to 25.7.
I have a problem with scaling of layers with FX when doing export or image resize.
If I go to "Export As" on an image and export the image resized (50% for example), layers with FX on them will export wrong. For some reason the export image includes scaling on those layers with FX on them. I belive the correct behaviour should be that it just exports the final raster image and doesnt touch anything else. Unless I am missing something? If i rasterize the layer with FX, it will scale correctly. However this is highly counterintuitive that I have to make a rasterized layer before exporting, makes no sense when export should be the final raster image regardless. I have tried "scaling options" on "image resize" but it does absolutely nothing.
The legacy "Save for web" scales the image correctly. See photos for reference.
I would say this is a bug with export as. I've never cared for that feature and still prefer to use save for web. Save for web was suppose to be removed, once Adobe got export as refined — doesn't look like that has hapened or will happe. Any time soon. It sounds like you need a workaround. I've been using Bridge's file export a lot, for multiple files. That way I often don't need to even open PS.
So, no response from Adobe on a bug that has been in their software since 25.7? I'm honestly tempted to cancel my subscription and go with a different package. It's not worth $720/year.