Hi Gauravmuk,
Welcome to Sony Community!
We're sorry to hear that you've been having this issue. There are default configuration settings that get triggered when the computer enters hibernation or sleepmode which can slow down or stop the Internet connection. You may check the setting under Power Option and make sure that the Wireless Adapter Settings is set to Maximum Performance. You may refer to this link for guidance, https://us.en.kb.sony.com/app/answers/detail/a_id/44444/p/48903%2C49902%2C91615%2C92204/c/65%2C66/kw/power%20option
For further assistance regarding your concern, please contact the Sony offices/Sony representative offices nearest to your place of residence in Asia Pacific region http://www.sony-asia.com/countryselector.html?hpid=countryselector:AsiaPacific. Due to proximity, they are in a better position to respond to your questions or concerns.