For newer Z wave devices, which includes the two that you listed, association group one is always the lifeline group. That should have the hub in it and only the hub.
As far as the other Association groups, that’s entirely up to the manufacturer and different models will use different groups for different purposes. But however they are going to use them, it has to have been listed as part of the application for Z wave certification. So the information should be on the official Z wave alliance products site.
When you create a direct association in zwave, literally all you are doing is having the hub give the trigger device permission to send direct network commands to the Target devices without going through the hub first. Seriously, that’s all there is to it. So you don’t do anything with the Target device. It’s going to get the message and then it’s going to act on a message, and it doesn’t care whether the message came from the hub or came from another device. Policing that is left up to the hub.
Creating an association means updating the firmware of the trigger device with the network IDs of the Target devices that it is allowed to speak to directly.
I don’t understand what you mean by saying “I have both devices set to group 2.“ That’s something you could do with zigbee, but it’s not how zwave devices work. so for now, I’m going to ignore the fact that you said that. You should not have to change anything for the minoston for this use case.
So let’s see how that Zooz model uses associations.
OK, it looks very straightforward. It uses association group 2 for basic on/off and association group 3 for dimming.
Now the first trick. With most zwave hubs you would just put the id of the minoston into group 2. But with SmartThings, you may find that the app status works better if you also put the hub into group 2. So start by trying that and see if it fixes the problem. Still leave the hub ID in association group one also, by the way. And don’t do anything with the association groups for the minoston. The association groups for the minoston are used when the minoston is the trigger, not when it is the target.
If that doesn’t fix it, then it seems likely that the minoston is just not reporting its change in state, which isn’t that uncommon for a plug.
I would report that to minoston and support and see what they say.
What DTH are you using for the minoston?