can not connect my home-assistant

**Home Assistant Android app version(s):** 2026.2.1

**Android version(s):** 16

**Device model(s):** Honor Magic 8

**Home Assistant version:** 2025.12.4 (Core) / Supervisor 2026.1.1 / OS 17.0

**Description of problem:**

When accessing Home Assistant through the Android app via external network (mobile data), the connection fails.

**Network configuration:**
- **Direct connection via DDNS** (no reverse proxy, no Nginx)
- **IPv6 only**: DDNS resolves to IPv6 address (AAAA record)
- URL format: `http://[your-domain]` or `https://[your-domain]` (direct IPv6)

**Connectivity test results:**
- ✅ Internal URL (WiFi/LAN): Working
- ✅ External URL via Mobile Browser: **Working** (Chrome loads the page)
- ❌ External URL via Home Assistant App: **Fails to connect**

**Key observation:** The app fails to connect via IPv6 on mobile data, while the browser on the same device connects successfully. This suggests the app's network stack (WebView/OkHttp) may have IPv6 connectivity issues or different handling compared to Chrome.

**Error message:** ``

Website not available
Website https://ha.example.com:8123/?external_auth=1 couldn't load.
net::ERR_NAME_NOT_RESOLVED

**Companion App Logs:**

[homeassistant_companion_log_1-2-2026_11-33-11.txt](https://github.com/user-attachments/files/24999402/homeassistant_companion_log_1-2-2026_11-33-11.txt)