I also have an Ikea Markus, an height adjustable table by the same brand, Lenovo Thinkpad Extreme Gen5, Lenovo Workstation Dock, and two Dell U2719D UHD Displays. I always blamed Lenovo for the displays randomly turning off and on, as the Laptop also tends to make other not so funny things when being connected to the Lenovo dockingstations, like throttling the CPU or delaying mouse and keyboard input … So glad I seem to have found the culprit reading this, at least for the display issues <3