Display Port On Motherboard: No signal

[Wackadoodle]

ASUS TUF Gaming Z590 Plus Gaming Motherboard (ATX, 11th/10th Gen Intel Core, LGA 1200 Socket, DDR4, PCIe 4, CFX, M.2 Slots, USB 3.2 Gen 2, DP/HDMI, Mystic Light
Gigabyte GeForce GTX GV-N1080G1 GAMING-8GD
G.Skill Ripjaws V Series 32GB (2 x 16GB) 288-Pin SDRAM (PC4-25600) DDR4 3200
Intel Core i5-10600 (base stroke: 3.30GHz; socket: LGA1200; 65 watt

The first time that I started the new motherboard, my monitor was connected to the DP output on the MB. Signal was fine. After setting up CSM for Legasy as instructed, there was no longer a signal from the port. I had to connect directly to the GPU. What did I do wrong? Is there a way to activate the DP on the MB? Thank You.

[STARRAIN@ROG]

Hi Wackadoodle,
Do you use the same DP cable when connected to MB or GPU?
If you disable CSM again, can you get the signal through DP output on the MB?
Are the bios all default settings except CSM enabled?
May I have the bios version?
Are you able to set Primary Display as iGPU in bios? (Advanced/System Agent (SA) Configuration/Graphics Configuration/Primary Display)
Thank you.

[Wackadoodle]

Hi Wackadoodle,
Do you use the same DP cable when connected to MB or GPU?
If you disable CSM again, can you get the signal through DP output on the MB?
Are the bios all default settings except CSM enabled?
May I have the bios version?
Are you able to set Primary Display as iGPU in bios? (Advanced/System Agent (SA) Configuration/Graphics Configuration/Primary Display)
Thank you.

OK, before I do all of that, which will take time. Does it really matter into which DP is used? Same cable used. The latest Bios. Thanks

[STARRAIN@ROG]

Hi Wackadoodle,
If you have the graphics card installed, and only connect one monitor, I suggest use the DP from the graphics card.
Thank you.

[Wackadoodle]

OK, I understand now. I went to Ton Hardware Forum. You are correct the DP on the MB is only for those who don't have a GPU Card. The card is the best output. Thanks. I was just curious. Now I am Happy!