Binding frsky DHT-U with crazy bee f4 integrated SPI frsky rx

Hi guys, I tried to bind a frsky DHT-U module to an eachine trashcan which has an inbuilt frsky receiver. The rx supports d8 and d16 mode, I am using d8 mode. The DHT-U has an V8 mode for non telemetry rx and a d_mode which is also d8 according to the specs. So both are using the same protocol right? I cant't geht it to work so maybe one of you guys can help me out ;)...