Chosen Solution

hello wish the all great weekend i want to ask why there is difference on wifi signal from iphone to another i have 3 iphones 8 plus two of them can not connect to the router while the other one can connect normally is this a problem on wifi antenna or what ??? please note : i tried to connect to the same router from a same distance the result is shown

It sounds like you have a wifi router that is weak or are to far away. One of the phone is just receiving the signal better. I would say it the router.

I agree with @barriphone You can go to your router and give it a try. If it doesn’t work, then you can switch OFF your router for 5 minutes after that switch it ON and try. I guess it will work.