Webroot DNS

We have one client that has the Webroot DNS crashing and respawning every few seconds. As a result is not filtering anything.
I have changed the profile of the device to remove webroot AV and DNS filtering, re added to the normal profile which reinstalled webroot with the same issue

Any ideas?

That sounds like it could be an issue with Webroot itself rather than the integration. If no other software is interfering with it, I’d reach out to Webroot Support. Their KB does suggest reinstalling Webroot if you’re seeing any sort of crashing/reloading. Official Support & Customer Service for Home | Webroot