Packet Demodulation error in GNU Radio for Hackrf SDR - SBand Radio set up connection. [SBand Radio Tx , SDR Rx]

I have a set up in my lab. I am trying to get the S-band chain of my ground station working. My set up is described as Computer connected to a HackRf SDR via the USB and also connected to the Sband radio via UART connection. I have a switch on the UART connection to put the radio on and off. My radio is terminated by an Sband antenna emitting frequency 2.245 GHz. My SATLAB Sband radio has GMSK modulation . I am transmitting from the Sband radio using a minicom interface and reception from the Hack RF. I am running a GRC flowgraph with the SATLAB SRS3 receiver and demodulating packets sent from the Sband radio. For this communication,I can properly receive pings and my QT spectrum shows a well modulated signal . However the message debug window prints nothing , I can not properly receive the demodulated packets. What could be the problems i can check for me to receive the demodulated packets. I have been at it for 3 days but with no outstanding progress. I verifies the offset frequency, modulation rate, timing errors and encoding.