setRadioMsg Using "NULL" to disable radio slot not working?

[SteelSampson 1]

I am trying to make a mission where you can only use the radio within the certain trigger areas.

This is what I have in one trigger:

ACTIVATION:BLUFOR, Present, Repeatedly.

CONDITION:this

On ACT: 1 setRadioMsg "Request Transport"; hint "Radio Active";

On DEA: 1 setRadioMsg "NULL"; hint "Radio INACTIVE";

I still am able to access the channel even when outside the trigger?

What am I doing wrong?

Thanks!

[Chris Wilkinson 3]

I am also having this issue.

[notproplayer3 5]

don't use quotation marks : 1 setRadioMsg NULL ;