HDMI 2, no video

I have my herelink module. I have connected my camera to HDMI 2 as micro HDMI and port 1 is empty now. But I am not able to see the stream in Solex for camera 2 or camera 1.

Is there any software modification I have to do to make HDMI 2 as prefernce. I have tried connecting to the HDMI 1 and its working fine and I have read that HDMI 1 is preferred one.
So can anyone suggest what might be the problem is ?
PS: I must connect my camera to HDMI 2 only. HDMI 1 is not compatible with my current setup

What is the led indication when you connect hdmi 1 and hdmi 2?

Did HDMI 2 work before?

Did the camera screen get dark after connect to hdmi 2 ?

Can you try to re-flash firmware for both unit ?