For the last few weeks, my Hub V2 Firmware 000.018.00022 is disconnecting and reconnecting multiple times a day. I have unplugged the hub, waited 30 minutes, plugged it back in, still issue. Have done a reset on the hub, still issue. Have moved the network connection from a gigabit switch to plugged directly to the router, still issue and new network cable, still issue. I have been online, using a vpn and voip at the same time it does one of it’s disconnects, so I do not believe it is my internet connection. Any Ideas Out There Would be Greatly Appreciated.
I’m having the same issue. Mine is late at night. It is plugged directly into a Wi-Fi extender which hasn’t been going down. I’ve unplugged it and power cycled it with taken out the batteries without success. I am going to try putting new batteries in it tonight since it has woken me up several nights with the push notifications. It’s only been happening for a week-10days. This might push my wife over the edge because of the nightly push notifications. She’s been tolerating the automations for now and thinks it is a silly boy toy.
Same here. Active/inactive all day
Be sure to report these issues to ST support. 
Just to isolate the problem. Why don’t you plug the hub into the main router?
Same here! No patterns at all, been about 10+ days for me.
Even stranger there have been multiple threads like this over the last couple of years and all of them just end, no response, no bumps, no follow ups…
People usually don’t post the solution or follow up when the fault went away.
I finally reset the device to factory, reinstalled and it got rid of the issues. Just be forewarned, you have to disassociate all zwave devices and reassociate the devices.