We have a case open with support for the conserve mode issue. We were running 6.0.x and they upgraded the box to 6.2.3. Still had issues. Their latest attempt to resolve it was to switch the box from proxy mode to flow mode for UTM. We've always used proxy mode, so I'm not sure what all that is going to impact. I have to check with my tech that is working on that client to see if it has made the problem go away or not.