I doubt the issue is hardware related but you can submit a ticket here: Subscriptions – Hubitat Support
Just wanted to point out all of that was probably not needed, as you found just powering down and unplugging would fix it.
My first recommended step is going to be Reboot the hub with the "Rebuild Database" option selected. Once that is done, shut down and remove power for 30 seconds to restart the radios.
See if that helps.
Also some questions, are you aware of any devices where you greatly increased the event and state history values on the device page?
What Apps do you have installed? What Devices?
Basically... all of the questions on this post ‼ READ FIRST - Before Posting in Get Help need to be answered to see the entire picture.
EDIT: Sorry one other thing, sounds like you have hub protect, how often do you have the cloud backups scheduled? There is a current known issue where sometimes the cloud backup will crash the z-wave and then fail. I think if you go to the cloud backup tab it will give you more details if it has failed.
