Always does that, I am using the screen on the right and the manage profiles window always comes up on top of the left screen. It's quite annoying. Reproducible: Always
I'm using a more recent KF5/konsole then you are - I've never noticed this issue on my 2 monitors. What distro are you using? Anything else that might be an issue?
Debian sid. However with the latest round of KDE upgrades, the problem seems to be gone.