It turned out to be due to two issues.
- First time connected the card it was detected during boot up and firmware/BIOS automatically restarted to complete the process.
- Up on reboot it switch the video from integrated GPU to the GPU connected on the PCIe_1 slot.
When it switched I lost display and was unaware it was due to the video output being switched RTX 3070. So I changed the slot to PCIe_3 and restarted the PC thinking there is an issue. When I changed the slot BIOS didn't adjust itself automatically (though I noticed in some occasions it does automatically detect the card and reconfigure new slot by itself). When I restarted again the card was never detected as the firmware / BIOS expecting it to be on the initial slot (SLOT 1).
Anyways, those are the two reason caused all the problems.
I was able to reset BIOS by removing the motherboard battery which cleared the previous GPU configuration. Then I reconnected everything back and started the PC which it detected the card properly. When I connected the HDMI cable to GPU I was able to get the video output as well. So that's how it was solved. It wasn't an issue with the card which was really glad to know.
I guess I would like to know if there is an easy way to remove a GPU from BIOS without having to reset (removing battery).