Desktop Mode not working

Hi,
I would like to use the Desktop Mode with my FP5.
The USB-C to HDMI dongle is working together with my Linux Laptop.
When I plug the dongle into the Phone, to external Monitor goes into sleep mode.
Desktop Mode is active and Phone is rebooted.
Tweaks in the developer option do not make a difference.
I have installed Taskbar App, but still no Desktop Mode.
What do I miss or what Im doing wrong?
What could I investigate or is there a log file to look at?
-Kuumaur

I am having the same problem with my FP5. I have tried the following two USB-C docking stations (both support DP-Alt mode):
Hatoku USB C Multiport Adapter
Baseus USB C Hub 7 in 1 Adapter
As with the thread starter, I enabled desktop mode in the Android settings. When I plug my FP5 into the adapter, the external HDMI display remains in standby mode and FP5 Android displays a notification that the USB port has been disabled due to moisture or an incompatible device.

Am I doing something wrong or did I merely try the wrong docking solutions? Can anyone recommend a USB-C docking station which definetely works with FP5?

I have a Dell WD19TB dock which reliably connects to my FP5. Display with desktop mode, audio output, keyboard and mouse, and Ethernet connected to the dock all work. However, charging of the FP5 doesn’t work, it discharges while connected to the dock. The notification “Liquid or debris in USB port” appears. There is also the notification “Charging this device via USB”.

A different display adapter, the Apple A1621, doesn’t work with my FP5.