If anyone is interested I actually finally got the Popp Outdoor plug to work.
If I choose anything other than "When Off" for "Turn on Indicator" for the "Generic Z-Wave Switch", it is not possible to turn off the device from the hub (only possible to turn it on).
When I have "When off" chosen, I can turn on and off the switch without any problems.
I was also in contact with the Aeotec/Popp support about this and they had the following comments:
After thinking about this one for a little bit, I think the description for parameter in Hubitat may be the cause here.
#### Parameter 3: Switching behavior when receiving wireless OFF
Size: 1 Byte, Default Value: 0
|Setting|Description|
| --- | --- |
|0|Switches off|
|1|Ignores Off command|
|2|Switches on|
|3|Switches on, when receiving off command and current state is off|
This parameter setting can determine how the switch reacts to an OFF command which is likely the cause here. I am unsure if this what controls that since it is a generic switch driver, but this setting here would make sense if that setting sets this.
Make sure Parameter 3 [1 byte] = 0 so that it can correctly turn off wirelessly when receiving an OFF command.
I thought the "Turn on Indicator" was if the LED light of the manual button on the plug should be on/off etc. when the switch is on/off.