BIOS not working with new GPU installed

A little help please. I have a HP Z440 that I’ve finally decided to upgrade a little, so I bought the 700w power supply and put in a GTX 1080. But with the 1080 installed I just get a black screen when I try to get into BIOS. But, if I put the old graphics card back in, I can get into BIOS. Is there something I'm doing wrong? Or is there a setting that I’m missing that affects this? Shouldn’t BIOS work regardless of which graphics card? The OS is Windows 10 with the most current updates if that matters.  I checked out the HP Z440 GAMING COMPUTER AND OTHER HARDWARE UPGRADES page but did not see this problem or a FAQ section.

As soon as I can figure this out I'm looking into updating the TPM to 2.0 and adding a PCIE M.2 card for my gaming drive.

SPECS:

HP Z440 Workstation

INTEL Xeon E5 1620 v3

16GB DDR4 (8GB x 2)

Samsung 500gb SSD x 2

Nvidia GTX 1080

GB LAN Port

700W Power Supply

DVD-RW

10 Pro 64Bit