@LorenzMeier, I've been trying to set up a PixRacer on a ZOHD-Orbit; which is similar to the Z-84. I'm using QGC v3.3.2 and PX4 v1.8.0 stack firmware. I've several times competed all sensors, radio calibration, etc.; but every time the Taranis transmitter connects to the D4R-II receiver, QGC reports MANUAL CONTROL LOST messages. I've tried both Generic and Z-84 airframe configurations, but same results.
I'm also experiencing issue #8475; which is still open.