I've had this issue for quite a while already and thought it occurred at random moments, but finally figured out how I'm able to replicate it.
I have 3 monitors and use a NVidia Surround setup and use the auto-splits.
The Windows 10 taskbar is on the center monitor with the side screens each having a DisplayFusion taskbar.
The strange behaviour is triggered when the windows taskbar gets focus, e.g. when I click on an empty part of it.
As long as my mouse cursor stays on the center monitor split all is fine, however when I move the cursor to either side monitor split, within a second the Windows 10 taskbar "follows" the cursor and moves to that side monitor and will position itself behind the DisplayFusion one.
This leaves a gap at the center monitor.
The taskbar will keep following my mouse cursor until the taskbar loses it's focus to a window or the desktop itself.
Opening the start menu by pressing the Windows-key will bring the Windows taskbar to the in front of the DisplayFusion one, so I can click on it again to give it focus and move my cursor to the center screen to move it back.
It doesn't matter if the taskbar is locked or unlocked, it will move regardless.
I've tried enabling and disabling various Multi-Taskbar related settings, but the only way to stop this behaviour seems to be disabling the Multi-Monitor Taskbar functionality.
Does anyone know what's going on and how I can stop this from happening?
Although it's easily "corrected" it happens quite frequent when working in Windows that it becomes quite the nuisance.
Here's a video showing the issue:
https://youtu.be/soMpMz3R_RQ
