Please help- multiple devices suddenly not online
Hello-
Every since 7/24, most of my "smart" devices are not online and I can't figure it out. My wifi is otherwise fine- my phone/computer/tv etc are all working fine. But my smart home devices are all offline and I can't get them back. I think they are mostly if not all 2.4ghz devices. And most of them do that thing where you have to choose the name of the device from your wifi list (on your phone) then connect to that network, then once connected, choose your regular wifi network to complete the connection. (sorry if I'm not explaining that well- hope you know what I mean!). So for most of them, I can find the device network in my wifi list and connect to it, but then when I need to find my actual wifi, it's just not there. The neighbors' networks and several other show up, just not mine. Despite the fact that many other devices are actively using that network without problem.
I have reset the entire gateway several times. I have rebooted the devices in question. I tried splitting the 5 and 2.4gh bands. Tried entering the SSID manually when I can't see it in the list. None of these things helped.
This is not a new router and I had not changed any settings. Everything was working just fine, and then suddenly I noticed one thing wouldn't connect. I thought it was the device. Then realized my thermostats, printer, smart outlets, etc were also all offline, so it's definitely not the specific devices.
Any help would be greatly appreciated!!!