xfce4-taskmanager 1.6.0: does NOT fetch GUI name of all my GUI applications

Version information

• openSUSE Leap 15.6
• xfce4-taskmanager 1.6.0

Steps to reproduce

1. open Taskmanager
2. open Bleachbit by Xfce-Terminal: bleachbit &, open Xfce-DOSBox by Terminal: dosbox &, open Xfce-MenuLibre by Terminal: menulibre &
3. look at Taskmanager for corresponding application, cf. PID: PID each is shown, but not GUI name of application

Expected outcome

• show Bleachbit resp. dosbox resp. MenuLibre in Taskmanager as GUI name

Cross Check

• A colleague did a cross check:

Using the same applications under KDE Plasma with systemmonitor instead of XFCE’s taskmanger, the application names show up properly. So it seems like an issue with xfce4-taskmanager.

Notes

• There may be more GUI applications with this issue. But these are the applications showing the issue on my system. As stated by the cross check, xfce4-taskmanager is affected, some other taskmanagers not.

Screenshots

Bleachbit

DOSBox

MenuLibre