This is the error after you turned off antivirus. The ConflictInMappingEntry looks like you might have conflicting port forward rules, or you have duplicated IP addresses on the LAN
Maybe you have UPnP enabled AND set up manual port forwarding rules for the same ports. In this case, either use UPnP and delete the manual rules, or use a manual rule and disable UPnP on the router.
It may also be caused by forwarding ports 50000-50002 - as mentioned, you only need to forward one port, the one that Roon tells you in its ARC settings. (On most machines this is 50000, but sometimes Roon seems to use 50002. Use the one it shows)
Or it’s a combination of these things.
The fact that this new error only seems to occur after you disabled the antivirus probably hints that you have two problems
- The antivirus blocking
- The issue with conflicting IP addresses or port forwarding rules
In this case, leave antivirus disabled for now and figure out the issue #2. Once this works, enable antivirus again and figure out issue #1, i.e. how to teach the antivirus to let the traffic through