I've not made too many changes recently to my (all Zigbee) set-up. I added a few buttons and a couple more Tradfri smart plugs (all repeaters are Tradfri) to HE, plus a couple of bulbs to the Hue bridge.
Things started going randomly weird. Sensors started dropping & despite re-pairing would drop again a day or two later. Changing batteries didn't help. Some lighting rules wouldn't work but devices were still present.
After a few days of chasing round the house with a pin to re-pair sensors I shut everything down (HE & Hue) while I went out for a couple of hours. Boot everything back up and hey presto - problems solved!
Got only knows how my mesh ended up FUBAR but rule #1 (turn it off and back on again) did the trick. Rule #2 is "if in doubt give it a whack with a Birmingham screwdriver" (non-UK peeps might have to Google that one!!)
I recently emerged from the same problem. I can't even say for sure what the problem was. First I think a few of my Sengled bulbs were going wonky. Oddly even though they are LED's they were sizzling hot. Also took down all of my Aqara devices, I just give up. Third I removed a few no name peanut plugs. Since all of that everything is working well again... Well Sonoff sensor battery changes still cause me issues, but I'll replace as I go.
Oh and forgot, all those things seemed to make things better at each step but the soft reset seemed to really clean it up.
If I were a bit more brave I would try to reintroduce some of that equipment but I'm smart home fatigued.
Due to my laziness and weariness I will only buy sensors that use AAA batteries unless it doesn't exist. No more button cells.
Introducing just one new device into an established mesh is a major event that must be monitored accordingly. Adding "couple more" can certainly have the effect that you described.
This measure precisely triggered the panic mode for your Zigbee radio and forced it to rebuild the routing tables (much like the Z-Wave repair process). So yes, adding new routers and forcing the radio to rebuild the routing tables can be expected to have the outcome you've observed.
@bobbyD what does this actually do to the hub and mesh?
I (eventually) guessed as much, hence forcing it to rebuild the mesh. It was the level of FUBAR that took me by surprise! Touch wood - everything's settled down & behaving as it should.
I've gotten into the habit of shutting down (20 plus minutes) HE any time I do anything with a repeating capacity.
Picture the hub as having 3 independent moving parts: the 2 radios and the hub's database. Devices are connected to the radio and the radio sends messages to the hub. Soft Reset removes one of the moving parts (the hub's databse) but doesn't have any effect on the other two. It is possible that you have had some issues with the hub's db in addition to the Zigbee radio, which the Soft Reset resolved.
That makes a lot of sense. When I removed some suspected problem devices things got better. They finally got back to flawless when I did the soft reset. I have added and removed mountains of devices with never doing a soft reset. Thanks Ikea buttons, Aqara everything, and Tuya this and that. Those 3 have moved my hairline south just a little bit.
Haha another Aqara victim. I too saved money(actually wasted 100's) with Aqara sensors that only work well on Aqara hubs and HA. I'm spinning up another HA instance to see if I can put all that wasted money to work.
The best day was when I removed all aqara devices. I only left the 6 button Opple switch, which is a literal nightmare to join, but very solid until battery change time. It's a Zigbee 3.0 device and might be more compliant to Zigbee standards.
Wonder if other HE folks have had a good experience with Opple?
I've got a few 4 and 6 button Opples. You're right - it's an absolute nightmare to get them to pair properly but once that's done they've been rock solid, although ALL of my repeaters are Tradfri.
Prior to rebooting, the weirdness with things randomly dropping off was mainly Sonoff sensors. The Aqara stuff seemed largely unaffected!
I also have a few Opple 2-way and 6-way Zigbee 3.0 buttons in use since Dec. 2020; they've been drama free. Unlike my half dozen Xiaomi round buttons, I didn't take any special care in joining them through compatible repeaters; they just work.