0.2.7.3-rc: no IPv6 Tor connections

0.2.6.10 works fine, with that I have > 200 IPv6 inbound connections from relays. With 0.2.7.3-rc I do just have 1 IPv6 from tor.noreply.org

From my mails :

My exit relay F1BE15429B3CE696D6807F4D4A58B1BFEC45C822 has an overall traffic of about 150 GB/day.

Few weeks ago I added IPv6 to the exit policy too. Since that time I observed the mentioned IPv6 traffic.

With the new Tor version I realized the decrease.

I verified that switching back to 0.2.6.10 gives about 200 IPv6 connections to other relays, whereas w/ 0.2.7.3-rc I do just have 1 IPv6 connection to tor.noreply.org.