#172 T530 is not useable with ThinkPad Mini Dock Series 3 with there HDMI and/or DisplayPort

I use a fresh build from 18 September 2023. The most connections from the ThinkPad Mini Dock Series 3 are working. The only connections doesn't work are the HDMI and Displayport. There is no screen detection during boot and at the booted OS (Debian 11) The microcode is in the cbfs, I don't touch it. Is there anything known about this issue and the important question, how can I/we fix it?