To resolve the issue of your Jumia app displaying "No internet connection," follow these comprehensive steps:

1. Check Internet Connection:
- Ensure your device is connected to a stable Wi-Fi or mobile data network. You can confirm this by trying to access a different app or website.

2. Restart Your Device:
- Sometimes, a simple restart can troubleshoot minor connectivity issues. Power off your Android device completely and turn it back on.

3. Restart Your Router:
- If you are using Wi-Fi, consider restarting your router. Unplug it from the power source, wait for about 10 seconds, and then plug it back in.

4. Clear the App Cache:
- Go to Settings > Apps > Jumia > Storage and select Clear Cache. This can resolve issues related to corrupted or outdated data.

5. Update the Jumia App:
- Ensure you are using the latest version of the Jumia app. Go to the Google Play Store, search for "Jumia," and select Update if available.

6. Disable Battery Saver Mode:
- Battery saver settings can restrict network activity. Disable battery saver by going to Settings > Battery and adjusting the Battery Saver options.

7. Check for Device-Specific Issues:
- Try connecting to another Wi-Fi network or turning on your mobile data to check if the issue persists. This can help determine if it is a device-specific problem.

8. Reinstall the Jumia App:
- Uninstall the Jumia app by going to Settings > Apps > Jumia > Uninstall. Re-download and install it from the Google Play Store.

9. Look for Outages:
- Check if there is a known outage or server issue affecting the Jumia app by visiting status monitoring websites like Is Jumia down? Check current problems and outages! - [learn more] or Is Jumia.co.ke down? Check current status - [learn more].

10. Contact Jumia Support:
- If none of the above steps help, consider reaching out to Jumia support for further assistance. They may provide additional insights regarding connectivity or server issues.

Following these steps should help you regain access to the Jumia app. If you need further assistance or clarification on any of these steps, feel free to ask.