AnymixPro Bug Automation does not work when rendering to a file

Hi, I’m using currently Nuendo 8.3.
In my latest 5.1 mix project I cannot get AnymixPro automation rendered.
Some audio tracks are routed to a 5.1 group where I use AnymixPro as panner. Target: letting it rotate. This group is routed to some more 5.1 subgroups, last is called 5.1_MASTER. Then it goes to the 5.1 out.
Playback works fine. But if I do an export of 5.1_MASTER group to FLAC (24 bit) the automation (the wanted rotation) is omitted. As the automation read button wasn’t set. But it is.

How can I get this working (without paying an upgrade)? Any ideas?

Regards, Mike

PS: ASIO Guard is enabled. Standard setting.