To reproduce:
- Change your crouch keybind to ctrl/command, and your sprint keybind to SHIFT
- Tooltip says SHIFT is the modifier to centre

- Place window without holding down SHIFT: Edge aligns as expected
- Place window while holding down SHIFT: Edge Aligns (not expected)
- Place window while holding down CTRL: Centre aligns (not expected)
- See reference image:

Tested as an issue on both Latticed window variations.