I had used S7 earlier and now using S9+. There is a real bug in all samsung galaxy phones from what I understand referring the open community forums. Problem: I am using HIGHSPEED internet here. Whenever I try to do some stress task with internet like, (Playing a HD song in youtube and trying to connect with a BT device, palying PUBG, or whatsapp video call etc...or whatever that requires internet) The phone wifi symbol will show a exclamation mark and the internet stops there. Turning it OFF and then ON will reconnect for a while and then it repeats. I tested this using my home wifi as well as public wifi, no luck. I need to get rid of this as it is very annoying and losing various things while I perform with internet. Samsung, better consider this error URGENT as I am sending this error report from the so called FLAGSHIP of SAMSUNG.
First Go to Settings-> General Management-> Reset and -> Reset Network Settings (No factory Reset) Restart your phone. Second Contact the Wifi Provider whether the data has been consumed or any defect in the router. If your problem is solved please click 3 dots and "Accept Solution"