Huh, thats odd! I think you might of been seeing an issue with DNS rebinding protection enabled on your network. Depending on your Android version 2025.15 will solve it, and 2025.16 (linked below) will fix it for all Android versions.
You can download the APK thats linked, and install it if you see the issue again; https://artifacts.plex.tv/react-builds/2025.16.0.966828397-4fa82/PlexReactNative-2025.16.0.966828397-4fa82.apk
