As reported in this post, there was a problem in the logic for dynamic datatypes with boolean values. The asset and the demo were updated to fix this issue and the datagrid be able to display unchecked values.

In this new version we have added a new action for client and server side named ParseJson_ToDynamicColumnsDynamicDataType. This action takes the same inputs as the previous but one. Instead of receiving one value for the datatype of all dynamic columns, it receives a list with each dynamic column name and its correspondent data type, allowing for each dynamic columns on the datagrid to have its own datatype.

Fixed a bug where one of the values of the last row would not show up