WIFI PROBELM WITH BRAND NEW IPHONE 8 PLUS

i have a problem with my iphone 8 plus my router and wifi and different devices working normaly but when i am in youtoube for example the device need to be refreshed so i can watch another video and loke i am in safari the phone loose connection all the time even if it says is connected i have the newest version of updates but still i have the same issue problem is not resolved with the new updates !!!!’ what shall i do ??! i use my iphone 6s for internet for god sake !!!!