Is that example a device type or a smart app? I think it’s a device type and from what I’ve read it seems like SendHubCommand behaves differently for apps than device types?
I found another example posted by @geko (here) that shows a SmartApp use of the call that doesn’t require the hexed IP iirc. Unfortunately, I’m not really sure where my code differs from that example, unless it’s in the HOST property of the call.