I had to soft reset my C7. I restored my last backup and devices etc seem to be back up. But, Hubigraph seems to be not working since then. My graphs are not loading up. On the graph configuration page, if I click the generated local up, then I can see graph.. but the preview or the time graphic does not load up.
Could you elaborate a bit please? In my case, Hubitat booted up...but I had no way to connect to it, as there was no ethernet cable working near it. I had to physically move the device to a different house location, where there was working ethernet.
Within each Hubigraph child device there is a drop-down to disable Oauth authorization. You might try disabling and reauthorizing the API and see if that works.