Set Up Problems RC7 PRO

Hi
I have several problems/Challenges in setup new Siyi RC7 Pro.
I have interest to have support or interaction regarding the right setup from the RC.

My Hardware Setup
RC7 Pro
Pixhawk C6
A8 Mini
RTK 4 base and mobil

All software is on the latest version (see pictures)

my topics:
connection RC7 Pro to air unit and Flight controller with UNI GCS works fine (Airunit Flight controller connected over UART Telemetrie 1)
connection RC7 Pro to Windows PC do not work (USB C Port ???
connection RC7 Pro to Airunit and Flightcontroller with Siyi QGroundcontrol installed on RC/ do not work ??
Please can you give support to have the right setup.
Kinds to observe ?

Siyi’s operatings instruction are a little bit confusing
I haven’t found some tutorials in the web.

Thanks and regards
Jens