initialValue on MultiSelectFormField not working!

[jabedbd]

I have tried to set initialValue value on MultiSelectFormField. but it's not working.

My dataset was like:
dataSource: [ { "display": "Running", "value": "1", } ]

And the initialValue is set to
[1]

[jtmuller5]

You need to set the initialValue to ["1"] for it to recognize it.

[david-kalbermatten]

To elaborate on @jtmuller5's answer...
If you set dataSource: [ { "display": "Running", "value": "1", } ], your "value" will be of type String. This means you need to match the type in your initalValue-List.