After IPv6 setup, OX works under HTTPS:, but not with DAVx5


I am running Open-Xchange (7.10.6-ucs5) on a UCS Replica Directory Node 5.0-6. I have configured IPv6 in the network. More precisely, I have a Vodafone cable connection (IPv6 only) with a prefix delegation /59 which I forward from the Fritz!Box to the pfSense.

I have activated the IPv6 configuration “SLAAC” for the UCS hosts that I want to reach externally. The hosts also get a correct IPv6 address. I can reach all systems externally via the browser (HTTPS). However, my DAVx5 (on Android) has not been able to connect since then.

Where in Open-Xchange do I activate IPv6?

with best