Not from the app–your phone talks to the cloud, the cloud talks to the hub and the hub talks to your devices.
If you’re saying that all you did was turn off with your phone using wifi to access the Internet instead of your cell network, it’s very unlikely that that had anything to do with it.
WiFi can Interfere with zigbee–but not zwave
Wi-Fi signals in the area can conflict with zigbee signals (but not zwave). But that would be the signal from the hub to the nightlight.
So the first question is what protocol does the nightlight use? If it’s zwave then your Wi-Fi has nothing to do with it.
If the nightlight is zigbee, then you can get some interference is Wi-Fi, but again, it’s not likely that it’s just your phone because your phone is already done talking by the time the hub finally gets the message to send a zigbee command to the nightlight.
but first: did you mean WiFi instead of cellular? Or Wifi without Internet?
Before we go any further, though, when you say your phone was “on Wi-Fi” do you mean just local Wi-Fi? Or did the phone actually still have Internet access?
Smartthings is a cloud-based architecture. Your phone app cannot talk to the hub except by going out over the Internet to the SmartThings cloud and then coming back over the Internet to the hub. If your phone is on your local area network but you don’t have Internet access the phone app will not be able to talk to the hub. ( I mention that because that is not true for a number of other home automation systems.)
back to zigbee
OK, so if your phone has Internet access while it’s on Wi-Fi and the hub has Internet access and the nightlight is zigbee, there’s a very small chance that there some Wi-Fi interference preventing the nightlight from getting an instruction. That should be easy enough to test. If it happens a lot, contact support.
It’s still a good idea to make sure that your zigbee network is on a channel that won’t get interference from your Wi-Fi network. But that doesn’t sound like the problem that you’re describing.
Zigbee channel 11 and wiFi channel 11 are actually very far apart. If somebody thinks they’re having interference trouble, a lot of field techs will just start by putting both the zigbee and the Wi-Fi on to channel 11 and see if that helps.
Unfortunately with smart things the v one hub could not reset zigbee at all, and the V2 hub can only change the zigbee channel if you completely reset the entire hub and start over, and even then it’s just random what channel you’ll get the next time.
The Phillips hue bridge allows you to select the zigbee hue channel through their mobile app, so sometimes you can use that as a diagnostic tool before trying to deal with the smartthings hub.
Well my Wifi are on 8 , ST is on ZB14. I just checked and Hue is on 15 . I’ll see if maybe Hue interference is partially to blame for my Osram lights randomly dropping off ST. I didn’t realize I could set channel for Hue. I only use Hue app to add bulbs and then control everything through ST or Echo.
That would sort of make sense, being as the rooms with the most Hue bulbs are also the rooms where I have the most problems with ZB devices dropping off network.
Hue chose 25 on its own when I clicked change channel. So I will have to see if over time if that helps with ZB mesh .
I chose 8 for my WiFi for the simple reason " all " of my new neighbors have Charter installed wifi modem/routers and they are all on 1 ,6 or 11. So putting mine all on 8 ( guest on 4 ) eliminated most interference . It was actually " amusing " to me. Charter was next door 2-3 times a week " fixing" their internet. Once I changed my WiFi channel I have not seen a Charter van in the driveway since.
Maybe not, time will tell. I just know the rooms with the most Hue bulbs , ( other than room where ST hub is ) are also the rooms I have ZB devices drop off the mesh the most. I figured it couldn’t hurt to change Hue channels . Hue chose 25 on its own when I clicked change channel.