We at Samsung understand your concern. Kindly follow the below mentioned step to improve the performance of the device:
1. Forget the Network:nGo to apps screen >Settings >Connections > Wi-Fi >Wi-Fi network >Tap and hold the Wi-Fi network that you're having trouble with until the menu allows you to select Forget Network.
2. Reset Network Settings: Go to apps screen >Settings >General Management >Reset >Reset Network Setting.
For further assistance, register your concern in Samsung Members Application (Samsung Members App > Feedback >Error report > Attach log file for any issue)
