Description:
While working with the library I noticed that sometimes my widgets completely dissapeared, and after some investigating I discovered that they are not deleted, but rather overlap with eachother. This behaviour happens when an item gets reset out of bounds after it has swapped with another widget. I tried to find the root of the problem, which seems to be caused by me using the maxRow setting, specifically maxRow = 1, but it most likely also occurs with other amounts. This behaviour does not happen without the maxRow limitation, as it then instead pushes the other widget down vertically. The problem can be observed in the 'two vertical grids' demo: https://gridstackjs.com/demo/two_vertical.html

Steps to reproduce:

• Open the 'two vertical grids' demo
• Start dragging a widget
• Drag over another widget (in the same grid), triggering them swapping
• Drag the widget outside of bounds, resetting it
• The widget is now behind the other widget

Expected behaviour:

• The state of the grid should get reset to before the widget gets dragged (without the swapping)
• Or, the other widget gets pushed horizontally instead (which I imagine is quite troublesome to implement)