why if I set every icon with the same constraints, the first tends to go down?

I'm trying to create a stack view that contains 4 aligned buttons. until I start the program in the view controller the buttons appear aligned, but when I run the program in the simulator the first button tends to go down.

How can I solve it?



Here there are some images that explain more the problem : https://drive.google.com/drive/folders/1NFhrP4QeVmeJuUt_dy0sAz_YArNW8cJg