Unable to edit a custom field in MWO

I have encountered an issue with custom fields in the MWO client. When I add an editable custom field under Task Information, I can successfully edit it from the MWO client. However, when I add the same custom field under Customer Information, I am unable to enter any value in that field using the MWO client.

 

Is this expected behavior, or am I missing a configuration step? How can I make the custom field under Customer Information editable in the MWO client?

Thanks 

Nethmini