I'm not sure why this doesn't work.
Got "Use Helper App" ticked.
I can set the values, but the actual ringer state is not changed.
When i the change actual ringer state via quick setting, i can read that the value has changed.
I have a Galaxy S23 and the global mode_ringer setting can be set and the ringer state is not changed.
Unfortunately this can happen for some of global, secure and system settings - I believe it's a limitation of the OS implemented either by Google or the phone manufacturer.
However, for the mode_ringer setting there are alternative macro actions that can set the ringer state to 2, 1 or 0 AND change the actual ringer state.
I've attached a screenshot of a macro with these actions.