cannot restore "About Dock Applet" window after minimize

[nmaxx]

System: Ubuntu 18.04 LTS Release 18.04
Package version: 0.85-1

Reproduction steps:
1) use a panel layout that includes the Dock and optionally the window list
2) right click on the Dock
3) choose "About..."

=> expected behavior: the "About Dock Applet" window shows up in dock (and window list, if present)
=> actual behavior: the "About Dock Applet" window is not listed in the dock (nor window list, if present)

4) minimize the "About Dock Applet" window

=> expected behavior: there is a way to restore the minimized window
=> actual behavior: the window is irrecoverably hidden

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[nmaxx (nmaxx)]

The bug is still present in 19.04 daily build.
Maybe removing the minimize button for that window could be a stopgap solution?