Sik radio not sending heartbeat

Hi fellow ardpuilot friends. I am having serious issues with a 915mhz xrock rtb box. I can see via mission planner the settings for both the ground and remote unit but for some reason when I try to connect via telemetry from the PC, the remote unit red led will blink once but mavlink will state after waiting for 30 seconds that there is no heartbeat. I updated the ground station driver but still not working. Any ideas as to what might be the issue? Thanks for all the help you may provide me with. Have a great weekend.

Are you sure mavlink telemetry is selected for the serial port it’s connected to? And correct baud?

yes. When i plug the rtb box (ground) to my pc, mission planner shows com8 and i notice that both radios have a solid green led. I don’t know if it might be a firmware related issue and I need to downgrade the driver to a previous version. Strange though is that on my tablet, when I try to connect the rtb box via bluetooth, it does pair,but still no heartbeat from the remote. I did had to invert the 6 pin connectors since there was no power coming in to the remote telemetry radio via the pixhawk. by any chance someone has the wiring diagram? will it be a cross cable issue?