Captive Portal sends RADIUS output accounting packets with zero value

[mark_orion]

I am testing 2.0RC1 with a daloradius managed freeradius server. I notice that there is no proper accounting for the downstream data - only upstream traffic is counted. A check with Wireshark reveals that pfSense sends Acct-Output-Packets / Acct-Output-Octets / Acct-Output-Gigawords with zero as value.
The attached file contains the packetcapture - have a look at the accounting requests sent from 172.16.1.112 (pfSense) in this test.
radiuspfSense.txt