What are the version and build numbers of your device agent?  Is it Android+ or Android-Enterprise device agent you are using?   (Please excuse me for asking even though you put Android+ in your post.   Many people, espeically newcomers, confuse the term Android+ to mean exactly the same as Android-Enterprise.)

Please note that many things that used to work on Samsung Android+ ELM device agent do not work any more on Android Enterprise device agent.   Results can also vary with device agent versions.

Please note that NOT all parameters reported with watchsettings can actually be set with script command.  Also, the script command is case sensitive, so you should use writesecuresetting  rather than Writesecuresetting.  Finally, I found that some parameters reported to be global are actually configured using argument -sec instead of -glo.  

You can use the above information to perform more tests on your device. Good luck.

Thank you for your response. It is an Android + Agent. 

Following up on RC's comment. The format for the script should be the following, with a lowercase writesecuresetting:

writesecuresetting -glo navigation_bar_gesture_while_hidden 1

If that doesn't work you can try: 

writesecuresetting -sec navigation_bar_gesture_while_hidden 1

And if that doesn't work, then 🤷🏻‍♂️