I have 2 C7's and lately, my primary hub has started to get really slow after about a day and a half of uptime - to the point where I've had to schedule a daily reboot or nothing works properly (this at least solves the symptoms).
I just can't figure out why as my hub doesn't seem to be working very hard:
I was hoping there was something I could do - being in IT I like to sort things myself if possible.
My house has multiple mains powered z-wave plus devices in every room and appears to be healthy.
That is worth a go.
What was tipping me off to a problem was motion lighting getting slower and slower. I'd walk past a sensor and it would trigger, then 10 seconds later the light might turn on, or not at all. Other automations were failing too including Basic and Simple rules.
That sounds like a ZW device having issues. One bad or failing device can kill even a good ZW mesh. I have, what I consider, a strong mesh with a lot of mains powered devices, etc and after debug I found one of my blinds went AWOL and it just crushed my ZW response time.
That's not completely surprising, I don't think a full repair every gets them all, it could have been asleep or just didn't complete the process in time; you can do an individual repair if you want. There's also a ZW mesh analyzer app that provides a nice snap shot of the state of the mesh. You could try that and see if any device has a slow response time, too many hops, etc.