I bought a new notebook (a gaming Asus TUF Dash F15 notebook, which I want to use as a workstation notebook), which also has an Intel Iris Xe iGPU (alongside an NVIDIA Geforce RTX3070). And that has exactly the same problems as my Samsung Galaxy Book Pro (also with Iris Xe iGPU) with USB-C and Thunderbolt docks with external monitors, with random dropouts and display timing mismatch problem. So there seems to be a general problem with the new Intel Iris Xe GPU architecture regarding the DisplayPort protocol over USB-C and Thunderbolt. Because I have six different USB-C and Thunderbolt docks, and with all of them the problems occur with these two different notebooks, each with an Intel Iris Xe (i)GPU. And of course, I've also tested through different cables and as well as different monitors, with absolutely no improvement.