Does not work on Arch Linux

[rotweaver]

Apologies in advance, as I am fairly new to linux but I cannot seem to get this program to properly detect my router.

Context:
Under Windows 11 & 10 the app can perfect detect my UPnP router via org.chris.portmapper.router.weupnp.WeUPnPRouterFactory
(This has been tested before writing this)

Under my linux distro (EndeavorOS latest) it does not, I will list the steps I have done below:

1. Verify my java version using /usr/lib/jvm/java-11-openjdk/bin/java -version which has an output of

openjdk version "11.0.30" 2026-01-20
OpenJDK Runtime Environment (build 11.0.30+7)
OpenJDK 64-Bit Server VM (build 11.0.30+7, mixed mode)

2. Run the app from the terminal via: /usr/lib/jvm/java-11-openjdk/bin/java -jar portmapper-2.2.4.jar
   The app launches and the only error I can find is

ERROR Unable to initialize network router: org.fourthline.cling.transport.spi.InitializationException: Failed to set modified URLStreamHandlerFactory in this environment. Can't use bundled default client based on HTTPURLConnection, see manual.
ERROR Cause: org.fourthline.cling.transport.spi.InitializationException: Failed to set modified URLStreamHandlerFactory in this environment. Can't use bundled default client based on HTTPURLConnection, see manual.

I have attempted to find out how to fix this and have been unable (perhaps my google-fu is lacking)
I apologize in advance if this is a skill issue on my end and not an issue with your app. If you have any pointers to direct me, please let me know and I appreciate you for reading this! Thank you in advance!