RE: U2417H, DP 1.2 daisy chain mirrors, but does not extend.
You cannot start with computer HDMI out to daisychain U2417H. It will have to be the laptop USB Type-C out port.
Computer USB Type-C out --> USB Type-C to DP cable --> #1 U2417H DP in (MST On)
#1 U2417H DP out --> U2417H DP to mDP cable --> #2 U2417H mDP in (MST Off)
Social Media Support
Run the PC pre-Windows diagnostics
Where do I find my Dell PC Service Tag or Express service code?
Out of Warranty Support