We were also able to break it on macOS Tahoe Beta 3. We noticed that we were reusing the JavaAppLauncher over and over again for all our versions so the same uuid for all versions, which should be unique according to TN3179: Understanding local network privacy | Apple Developer Documentation#Build-time-considerations. Local network privacy uses your main executable UUID as part of its implementation. If your main executable has no UUID, or shares a UUID with other programs, local network privacy may behave weirdly. But what else should be unique so the app will be seen as a unique application? CFBundleIdentifier? What if you install applications in de same folder will the local network privacy settings be reused?

Out of curiosity, I installed macOS Tahoe 26 Beta 3 and tested the application, it appears to be working without any issues.

With a test project do you mean to strip the complete java application and keep only the part that is not working and build it in Xcode?

Still unfixed on macOS 15.5 (24F74)