When dragging tasks when custom Grid regions have been used, a lot of errors appear:
Uncaught TypeError: Cannot read property 'getBoundingClientRect' of undefined
Uncaught TypeError: Cannot read property 'startDate' of undefined
Uncaught TypeError: Cannot read property 'draggedEntities' of undefined
I've set up a Codepen: https://codepen.io/isazulay/pen/xxdLeeO
When not using these custom columns, everything works fine.