I tought there used to be a way to set this from within Mendix…
Anyway there is a class within the grid which controls this: mx-datagrid-column-resizer
If you create a new class, something like bellow and put the class on the datagrid. The option will dissapear:
I have tried code as below as you have suggested and thankfully the cursor “column resizer” disappeared.
But it can still be resizable when the user tried to move the other columns such as col# over 5 in below.