System Infos:
DisplayFusion Pro 12.1.2 (Beta 1)
Random Applications
Windows 11 Pro v26H2 Build 26300.9550

Similar to a firefox problem I saw from 2024...Applications will open and position themselves behind the DF toolbar when it is positiond at the top of the screen...the only solution i've found is to select the icon and move the app to the next monitor, where it will display below the toolbar as expected.
Attached image happens to be Samsung Magician, but this occurs with other apps as well, and their popout context menus...