I recently purchased the Hubitat C8 to be my Zigbee hub and for future Z Wave, etc devices and it integrates with Home Assistant.
The C8 is powered by the provided USB C cable and power adapter. It is connected via Ethernet through a managed switch. The network settings are set as a Static IP.
There are a whopping 6 ZigBee Sengled Lightbulbs and 3 Philips Dimmer Switches. That's it.
Yet, for reasons that are driving me insane is that it will run fine for a random period of time without any issues... until suddenly... the Web UI just stops responding and thus none of my Zigbee devices work.
I thought Hubitat would be better than a $30 Sonoff USB Zigbee Stick and I had no issues with that Zigbee stick except I was tempted by Hubitat and also liked the idea of having a single hub with antenna for better range.
However, when I wake up and can't turn on the lights and then have to go to the hub, unplug it and plug it back in, and then wait for things to reload...
Did you set the Static in the hub network settings, or are you talking about an Address Reservation on your router?
Do you have any devices that have Jumbo Frames configured? That is known to kill the interface.
That has the possibility to corrupt the database. You should try a Soft Reset and Restore. Be sure to download your backup to your desktop first. That will clean the corruption without losing any rules or devices you have paired. Soft Reset | Hubitat Documentation
You really should answer the questions in the post below to help the community and support to assist you:
I have it as a DHCP reservation on my router and also set the static IP on the device itself.
In regards to Jumbo Frames, I do have several devices (including my Proxmox server with Home Assistant) with Jumbo Frames enabled as most of my network switches are multi-gig with 10G and my hard-wired devices are 2.5G or faster. That said, the Hubitat is on a 1Gb managed switch that's just for IoT devices (YoLink, flic, etc) and don't have any issues with the them.
Do I really have to choose between configuring devices to have 1500 MTU or Hubitat? It's just odd that all my other devices, like wireless devices, Google TV, Roku, have no issues but it would break the Hubitat. Why is that?
Also, sorry for not posting the logs, the Hubitat was down at the time of originally posting and is unavailable again now. If I get the opportunity to have it stay online long enough, I'll get some logs. However, I do know that I'm running the latest firmware. I've tried rebuilding the zigbee network and rebooting that.
Also, of the device is completely unresponsive, is there a better way to get back online besides unplugging it? I do know that it's generally bad to unplug devices while they're running, but I don't know what else to do with the Hubitat.
Yes and no. Jumbo frames will kill the c5/c7/c8 hubs. It's a known issue and not really fixable at this time. The solution is to get an old 5 port hub (not switch) that does 100mb max. This will prevent JF's from passing., Or simply turn off jumbo frames. JF are unreliable anyway. You don't really need them on in a home network... Hell we turn them off in most data centers we're in as they do nothing but cause problems because there is no standard. So you constantly get 2 different vendor devices bumping heads when you use it.
It apparently is very easy to misconfigure a Static on the hub. In most cases that is unnecessary, unless you have a very unique network. You probably should be running DHCP on the hub (the default and suggested setup) and the reservation on your router. In either case, you shouldn't be using both a Static and reservation, it is one or the other.
@neonturbo - I usually just do DHCP reservations and not both. In this scenario, I was just trying to figure out what could be causing the problem and will take out the Static IP from the hub.
@rlithgow1 - Thanks for the advice! Rather than buy a new device, I first went into my switch and changed the port speed from Auto Negotiated to 100M, and, at least for the past few hours, it's remained online. Getting another switch isn't expensive; I found one for $10. It's more like taking up another power outlet and taking up space. However, I'd give that a try if changing the port speed doesn't improve it's reliability. Also, I went into the Home Assistant VM on Proxmox and set it's network adapter's MTU to 1500, since that would definitely be hitting it the most.
I apologize for the hostility in my original post. I do like the Hubitat very much when it's working and want it to work. However, at the time of the post, I had pretty much each family member come to tell me that X light isn't working, etc. I'm like the IT guy for the entire house, and I was getting bombarded and had no idea what could be causing it to go offline. I sincerely appreciate your professionalism in your responses.
Yes, I'm sure you've already changed it, @ajtatum, but if not, remove the static IP on the hub and let your router IP reservation do the heavy lifting.
And as you'll see, turning off jumbo frames on your home network will do nothing but make it more reliable and easier to use w/a wide range of devices. Just not really useful on home networks...very common misunderstanding.
Not necessary, but definitely appreciated and earns you "mature human" points. There are a lot of thick skins around here, as most people only show up when they have a problem, so things do tend to start out "hot" and then cool down.
Hey - I just wanted to post an update. After changing the port configuration on my switch from "Auto Negotiate" to "100MB" and changing my Home Assistant VM to have a 1500 MTU, my Hubitat has remained online since my last post! Thank you for your assistance!
There are a lot of thick skins around here, as most people only show up when they have a problem, so things do tend to start out "hot" and then cool down. 
