ST hub keeps going offline

For the second time this week my ST hub has gone offline while all other devices connected to my router continue to function. I got it working the last time after power cycling the router twice, but I am wondering if the experts here could offer some thoughts as to why this just started happening and how to prevent it.
I have made no changes to my network neither added any new devices, so whatever is going on is between the router and ST. It’s just odd because even though I’ve had many issues with ST operating reliably it has never gone offline. Now twice in one week.
FWIW - I have always had a static IP assigned to ST, and the Hue hub connected to the same router continues to function properly.

That happened to me when I first got the system. I had to completely remove my hub from ST and start over. Definitely contact support before doing that, hope you get a better answer than that.

Thanks. I was able to determine it’s an issue with DHCP, but I’m not sure what to do about it. Despite having a static IP the ST hub is intermittently being assigned a 10.xxx IP instead of the 192 series of my LAN. I don’t know enough about this to understand why it’s happening, but when it switches to the 10.xxx series I can no longer communicate with it.

Have you messed with your router’s DHCP at all? I don’t touch that stuff, I know enough that I probably could but I don’t see a need for it, as long as hostnames don’t change I don’t care.