After uninstalling and reinstalling all the gateway agents it appears to be working again for us (Doesn't take long but that is A LOT of uninstalling and reinstalling when you have a lot of sites). I'm not doing anything too aggressive with KNM, just monitoring router bandwidth/resource utilization and ESXi servers.
I've also noticed the same behavior where a site will go offline or silently go offline in 9.2 (Still green but not monitoring) where I have to uninstall and reinstall the gateway.