Video output does not work with Fujitsu Siemens USB Port Replicator PR09
The Librem 5 connected to a Fujitsu USB Port Replicator PR09 with two DisplayPort displays, does not detect the displays. When the Librem 5 is connected no output is shown on the displays. The displays are also not detected in GNOME settings. However, charging, mouse and keyboard do work.
For further details see this forum thread.