When drag a column and drop outside the grid, the column disappeared from the grid and there is no way to return it unless refreshing the page.
This issue is applied to all demos on the grid's website. ex. https://www.ag-grid.com/javascript-grid-sorting/index.php
if you don't want the column to dissappear, set suppressDragLeaveHidesColumns=true
I have the same problem, but I want it to have the drag and drop functionality. The columns should appear in the Column Menu to select it again. The columns is just shown again by refreshing the page.
@ceolter thanks that did the trick
Here is the full list of properties for reference: https://www.ag-grid.com/javascript-grid-properties/
Most helpful comment
if you don't want the column to dissappear, set suppressDragLeaveHidesColumns=true