Optiplex 3090 Ultra Display Problem

3090 ultra has 

• One DisplayPort 1.4 ++ HBR2 support over rear standard DP port

The Dual-Mode DisplayPort™ or DisplayPort™++, shortened DP++, enables compatibility to DVI and HDMI. So the connection via relatively economy-priced adapters is provided.  you just need a simple passive DP to hdmi adapter to connect 3090 Ultra to hdmi monitor.

Thanks for the link.

According to the description of the monitor I purchased "The single-cable USB-C solution combines 65W power delivery with video, audio and data transmission in one cable ..."

Do you know why this would not be true?

3090 Ultra has 

• 1 USB 3.2 Gen 2 Type-C port with Display Port Alt Mode/Power delivery (rear)

DisplayPort over USB Type-C 

#6 USB 3.2 Gen 2 Type-C port with Display Port Alt Mode/Power delivery

Adapters and Adapter cables are available to connect DisplayPort over USB Type-C to DisplayPort, HDMI, DVI, and VGA monitor inputs.

Re: I assumed I could get video over USB C cable. Apparently not true.

what adapter are you using from USB C of 3090 to HDMI of monitor?

Guess I'm a bit confused. I had only the USB-C cable connected from the 3090 Ultra port to the USB-C port on the Dell monitor; no other cable was connected.

what is Dell monitor model?

for example Dell USB C monitor U2520D needs to Use the Input Source menu to select between the different video signals that may be connected to your monitor.

I have the Dell 27 USB-C model S2723HC.