To stop a Mac window from snapping when you drag it, open System Settings, choose Desktop & Dock, scroll to Windows, and turn off the specific drag behavior that causes the problem.
Identify the trigger before disabling it
Apple currently exposes separate options for dragging to the left or right edge to tile, dragging to the menu bar to fill, and holding Option while dragging to tile. Reproduce the action and note which screen region and modifier produced the highlight.
Disable one matching option, then repeat the exact drag. This preserves evidence and leaves other useful tiling methods available.
Keep intentional tiling if desired
Turning off drag triggers does not require abandoning tiling. You can still use the green-button menu, Window menu, or configured keyboard shortcuts. This is useful when accidental edge activation is the problem but deliberate layouts remain valuable.
If snapping continues, check third-party window managers and automation utilities for their own drag zones. Disable one tool’s feature and retest rather than resetting all window settings.
Distinguish fill from Mission Control
Dragging to the menu bar can fill a window, while dragging all the way through the top edge can open Mission Control. Record which visual state appears before changing settings.
Wallo does not snap, resize, or tile windows, so grouping a window in Wallo should not trigger geometry changes. Reproduce movement outside Wallo to identify the actual owner.