Dear Samsung Member,
Greetings from Samsung Customer Support!
We acknowledge your query and apologize for the same. To resolve your device network issue please visit this link: https://www.samsung.com/in/support/mobile-devices/samsung-galaxy-smartphone-how-to-optimise-network-...
In case the issue still occurs. Please register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
Thank you for writing to Samsung.
Samsung Customer Support