We recommend you to reset the power supply of the interface converter after having changed the corresponding settings.
If after that the problem still remains, it is probably due to outdated version of your firmware. In this case we recommend the following solution: please, study the video-lesson «Connection and settings of ZETSENSOR series products» (https://zetlab.com/videoyrok-zetsensor/).
This video describes connection and setting process of the digital sensors (by the example of RS-485 line). Your particular question is explained at 4 min 40 sec of the video,
We hope it will help you!