Can't write with Modbus TCP

I am using FactoryStudio 9.2 Demo and have modbus Tcp Master set to chanel. I have created the node for my slave plc and some points with read/write access type. In the array (and watch) I can read the values ​​from points (coils and holding registers) but I can’t write to those points. Is it because I’m using demo? On the site I downloaded the demo from the only thing it says about the drivers is that it includes all the standards.