The problem is the server of the website that you have reached is slow .
And another thing is only if u open chrome or UC browser and don't browse any thing ,or if u stay on a single web page then the speed will automatically decreases.
Try to use broadband with Wi-Fi router for good internet access 😉
Dear Samsung Member,
Greetings from Samsung Customer Support!
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).
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Samsung Customer Support