Before connecting the second monitor all icons stayed where they were relative to each other when scaling them (with Ctrl + mouse wheel).
However, after connecting the second monitor and trying to scale desktop icons (they are all placed on the 1st monitor) they all move weirdly. They would never stay in the bottom of the screen or on the right part of screen. I suspect it could be because the monitors have different resolutions: the 1st one - 2560x1440 and the 2nd one - 1920x1080. And the icons on the first monitor position as if the resolution was 1920x1080 not 2560x1440. I can put them in those parts of the screen but after scaling they all move from there to the middle of the screen.
I don't think this should be happening. I have already experimented with alignment to grid or auto arranging icons - that didn't do anything.
P.S.: It actually happens only when the scale of the icons becomes small (i don't know how small because there aren't percentages, just scroll wheel). If the icons are big they scale normaly, but if they are small they snap to a specific part of the screen (what seems to have a size of 1920x1080)