Have you switched the RAW &JPEG pair to use the RAW as the original? Use the menu item "Image > Use RAW as Original".
Are you using the command "Image > Edit with > Adobe Photoshop" to pass the image to Photoshop or are you opening the photo starting from Photoshop using the image browser in Photoshop? In the Media browser you will always see the jpeg previews of the photo, not the original RAW files.
When I want to pass an original RAW file to an external editor, I am using the External Editors extension, available from the AppStore. Once installed, this extension can be called from Photos in Edit Mode from the menu with the circled three dots. In external Editors we can specify, how an original file should be passed to the external editor - as RAW, as TIFF, or converted to DGN.
There is no way to pass a RAW image to an external editor, if the image has already adjustments applied. In the case you will have to revert the image to the original, or it will be passed to the external editor as JPEG.