asrock b760m pg lightning/d4 problem with VGA card

CPU Intel 147000 (UHD770)

VGA Graphic Card RTX3060

Background:
1. without plug in RTX3060, i can boot the system with built in UHD770 connected to HDMI monitor, and able to press del key to enter bios and everything work ok.
2. From the BIOS i set primary display as UHD770 (this is requirement the primary display must be UHD770).

Problem:
1. when i plug in the RTX3060 to PCIE without power on the second monitor with RTX3060, i can boot the system and it will show boot up screen on my primary HDMI monitor. however if i press del key to enter BIOS, it will hang in BIOS with 1/4 of BIOS screen showing.

2. if i power on the second monitor and press del during boot, then i can enter BIOS correctly in my primary monitor.

3. had changed few setting in the BIOS, including not using full HD in BIOS, the glitch is always need to power on 2nd monitor which connected to RTX3060 in order to enter BIOS correctly with UHD770 primary monitor.

expectation:
1. UHD770 should be able to enter the BIOS when a graphic card is inserted to PCIE, no matter if the second monitor is powered on or not.

i am willing to provide more info if asked, i really need this to be fixed and i am sure this is workable, my previous PC was MSI B660 Mortar and it work perfectly in the same setup.
i need the primary GPU to be UHD770 because this is a remote monitored PC that RTX3060 need to do something else.

thanks.