In KWin, how to snap windows to side independently on separate virtual desktops?

[Fedora KDE] Assume I have two virtual desktops (or activities, the issue appears there too). I have two windows open on desktop 1 - one snapped to the left edge and one to the right edge. Similarly on desktop 2 - one window snapped left, one window snapped right. That is, I have four windows, each covering half the monitor. On desktop 1, I grab the divider between the windows and change the size of the windows. For example, let's make the left window cover 3/4 of the total desktop. Now, what bugs me is that the sizes of the windows on desktop 2 changes as well. I don't know where in the settings to stop this behavior, and I suspect there may not be an easy setting, *because* is identical for virtual desktops and for plasma activities, so it seems to me that the problem is fairly deep. But: I don't know. Perhaps there is a way of correcting this - so my question is, if that can be corrected, how would I do that? Searching only gave me various forms of "here's how to enable snapping in kwin" or several year old "check out my script for enabling window snapping in kwin". I haven't installed (I don't think?) any such script so I suspect I've been using something that's now built-in but I haven't figured out where to find the documentation of that particular functionality. Thanks!