I just tested the animation index again after reading wimf's post about it.
Changing between two talk animations by changing the index to 0 or 1 seems to work als it should. (Yeah! Thank you devs!) But I can't call a third animation in the same direction. Animation index = 2 gets ignored.
Edit: ok, forget it. Whatever I did different now, it just worked for 6 animations of the same direction. Each animation showed up when it should.
Thank you so much for fixing this! :-)