It seems, that outgoing traffic from interfaces is wrongly calculated (or ignored) in the flow monitor
Tested:
Downloading a file from NAS: Client RED ==> UTM ==> NAS
UTM Interface (IN)
- Shows on Interface in Dashboard ~7,7 MBit IN (OK)
- Shows on the RED Interface in Dashboard ~7,1 MBit IN (OK)
- Shows in Flow Monitor ~1 MByte/s for RED traffic (OK)