after installing Ubuntu 18.04 (fresh install, no upgrade), I spent some time to get a workspace grid with my previous keyboard shortcuts working (see Workspace layout in Ubuntu 18.04 [duplicate] and Ubuntu 18.04: Put window into screen corner).
This basically works fine, but it interferes with the keyboard shortcuts to split the view ("Maximize window", "Restore window", "View split on left", "View split on right") using the Super+Arrow key combinations.
When setting my shortcuts, these are replaced and everything is fine. But after a reboot, the view splitting shortcuts are set again and lead to keybinding conflicts (e.g. Super+Up is now set to "Move to workspace above" AND to "Maximize window"). The view splitting shortcuts then usually take precedence, so if I want to switch to another workspace, the window is modified instead.
What could be reason for this restoring of original keybindings and how can I avoid it?