Hello @Shourove_Sharma ,
Welcome to our community.
Here are some steps you can follow to troubleshoot:
1. Wait a few seconds: Sometimes, the real-time rate display in the Tether app may be delayed. Please wait for a short while to see if the rate updates correctly.
2. Check your network topology: The real-time rate may not be accurate if you are mainly using LAN (wired) communication within your network, such as when a NAS device is downloading files or streaming videos inside your local network. The Tether app's real-time rate is designed to show Internet traffic, so internal LAN traffic may not be reflected accurately.
3. Reinstall the Tether app: Try uninstalling and reinstalling the Tether app on your phone to ensure you have the latest version and to clear any potential app glitches.