Java: the LanguageTool window can not be shown after hiding to the system tray

After running java -jar languagetool.jar I can use the menu option:

  • Hide to System Tray

The resulting icon can not be used to restore the window:

Environment

6.7-SNAPSHOT (2025-04-05 18:50:52 +0200) from https://internal1.languagetool.org/snapshots/

KDE Plasma

grahamperrin@mowa219-gjp4-zbook-freebsd ~/d/LanguageTool [SIGINT]> pkg iinfo openjdk23
openjdk23-23.0.2+7.1_1
grahamperrin@mowa219-gjp4-zbook-freebsd ~/d/LanguageTool> uname -mvKU
FreeBSD 15.0-CURRENT main-n276254-22fe926a62b7 GENERIC-NODEBUG amd64 1500035 1500035
grahamperrin@mowa219-gjp4-zbook-freebsd ~/d/LanguageTool> 

Reference

https://dev.languagetool.org/http-server