Help me (networks problem)

[Kawsar4s]

My mobile has a network spot, what could be the problem, how to fix it, data connection is slow.

See screenshot 

[Samsung_Support2]

Dear Samsung Member,

Greetings from Samsung Customer Support!

We apologize for your inconvenience. To resolve your device network issue please visit this link: https://www.samsung.com/in/support/mobile-devices/samsung-mobile-network-issues/#:~:text=1%20Check%2....

For further assistance, 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.

Warm Regards,  
Samsung Customer Support