Thanks for the reply, it appears docking in any horizontal orientation will allow for icon movement. Neither vertical orientation (left and right edge) works.
Version of ObjectDock: 3.01
Windows 11 24h2 26100.4946
I can do the workaround for now. Might want to consider fixing it for vertical orientations, or at least include that note about needing the dock to be horizontal for dragging icons in the in-app help.