ZIgbee devices dropping off when presence sensor arrives

I have approx 40+ zigbee devices distributed over the hub are 4 zigbee routers I’ve made. All works fine in normal operation but I’ve noticed that each time my daughter comes to stay every 2 or 3 weeks with her presence sensor a random set of my devices drop off usually 10-15 of them. Some will reconnect given a prod on the button, others I have to completely re-pair.

An ideas on cause or how I remedy this to stop it recurring ?

that is interesting. Maybe she has her phone hotspot on all the time, which could interfere with with your zigbee hub/routers. Or she plugs in her super-noisy phone charger. Try having her turn off her phone for 20-30 minutes.

Rather than re-pair any one device, try turning off the hub or whatever routers you are referring to, turn it off for 15 minutes then back on, to try to make the hub rebuild the mesh.

What are the zigbee routers you’ve made?

Her presence sensor shouldn’t have anything to do with it. I agree, I would suspect other environmental changes caused by her visit, in particular just greater use of Wi-Fi. If she’s watching a streaming box, using Wi-Fi on her phone, and running Wi-Fi on a tablet or laptop all at the same time that’s adding a lot of potential local interference that could affect zigbee devices.

Have you checked the channels on your smartthings hub and Wi-Fi router for potential interference?

I forgot the other lifestyle possibility that often comes up with visitors is that they turn things off or even unplug them and that weakens the mesh.

It’s like the classic mystery story where the solution turns out to be the cleaning service coming through the office building unplugs a particular device every day in order to plug in the vacuum cleaner.

If you made zigbee routers, I’m assuming those are plug-in modules, is there any chance that she’s occasionally unplugging one? Or turning off smart bulbs at the switch? Stuff like that.

HI guys, thanks for the feedback, I should have said the presence sensors are Samsung ones keyfobs not mobile phone, and may be it’s just coincidence - but I always notice after she has stayed and it’s always OK in between.
However I did some fault diagnosis this afternoon and saw that the reason I was losing devices randomly was the routers were dropping the connection to the hub - so all direct connection device were fine but for some reason the router connections were lost (but between the routers they still connected !). I’d say it looks like the encryption keys were lost so the routers could not handshake with the hub, but why ? and why could they all talk to each other ? - and seemingly each time she comes round.

ANd yes already realigned network channels much earlier in the year in case that was causing any issues, so should be fine now they are at maximum distance.

No she doesn’t touch any of the routers I have plugged in (yes plugin zigbee module types)

Have reconnected everything and all looks good will continue to monitor.

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Under those circumstances, I would still wonder if the Wi-Fi is being used more extensively when she’s there. Wi-Fi and Zigbee operate in the same bands but wifi has a much stronger signal so it can drown out nearby zigbee. The interference might be bad enough that your router devices are missing their check ins.

You’ve got to have a LOT of wifi to interfere though. I live in a condo and there are about 15 wifi networks within range of my unit and I have never had a problem with devices randomly dropping off my network.
I would suspect you have some bad routing in your zigbee mesh. Did you do the zigbee “mesh heal” technique that was described above? Try pulling the power (and batteries) from your ST hub for at least 25 minutes. Then plug it back in. Your zigbee devices will reroute back to the hub when your hub is powered back on. Don’t pull the power from your devices during this time. They have to realize the hub is gone in order for the process to work.

Oh yes have tried the zigbee network rebuild procedure in the past but each time I have had to readd the devices. Today worked better actually looking at the routers and i know what to check next time. Thanks for the input guys & merry xmas.

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Your devices were deleted from your hub when you unplugged your router for 30 minutes? Or did you not wait long enough for all of them to come back online. That’s kind of the point of the procedure. Devices will find a new route to the hub. So, i would expect them to all not come back online instantly. You are screwing up the procedure if you interfere with the recovery.

I have done it at different times but at least once I have left it over night.

After powering back on? And you still had devices that were offline or that were deleted from your Hub? You keep giving like 75% of the answer to the question man…give me a little help here.

Well yes i think i didnt see that any of the disconnected devices reconnected via this process but i may have missed 1 or 2. I didnt do it this time. But today i saw the devices were still paired to the routers but as i said before the routers had lost their connection to the hub, although they could see each other. So in Xctu i could see the other routers and the connected devices for those routers but not the hub. Hence when going in via the app ie viewing from yhe hub those devices showed as disconnected.

If they’d lost connection to the router, how could you tell that the devices below that module were still connected? That doesn’t really make any sense. If a branch is missing, you don’t know what’s happened to the other devices on that branch. You’re assuming they stayed connected, right?

No i connected one of the routers to xctu and saw it had connections to 2 other routers and they each still had end points connected.

As i said before it was as if the routers (plus their connected end points) lost comms to the hub . And i assume, didnt check, it was those endpoints showing as disconnected in the app.