I have been dealing with this issue for a while. I have found some work arounds to get around the problem but It is very inconvenient. If I create the same size document (pixels) in illustrator and Photoshop then copy an object from illustrator and paste it in photoshop, photoshop resizes the object to fit the canvas. I have attached some photos of the document setup in case I'm overlooking something. If I do the same thing but set up the documents in inches I do not have the problem or if I set it up in inches and then change the dropdown to pixels it works fine too. any guesses on what the issue here is?

Update: I just realized when I type in the pixel dimensions in each application and then before creating the document I switch it to inches the sizes are way off. Photoshop is 6.4x3.6 (1920x1080) and Illustrator is 26.6x15 (1920x1080).