Thank you Chris! So for reasons I don't understand, it's now working, and I've been trying for several days. I did install both the Dell Display Manager and OS driver. I also reconnected and disconnected the HDMI cable.
I have a Lenovo ThinkPad X1 Yoga Gen 7 laptop with a Thunderbolt 4/USB-C port and a Dell S2722QC monitor. I am trying to use one usb-c cable to connect the monitor, power, and peripherals (data). Power and data are working, but the display is not. I've read posts about cables, and I replaced the dell-provided cable, with this Unitek cable, but it's still not working. On the laptop, the S2722QC is showing as a second display, but the display is labeled as inactive. Any help is greatly appreciated.
S2722QC, Lenovo ThinkPad X1 Yoga, no video