My macbook air 2015 with YOSEMITE everything works normally. But if i update to EL CAPITAN or ABOVE it will have wifi problem, like can't join to the network even i entered correct password. Sometimes it can join to my wifi network randomly but the speed is very slow and its will make (affecting) my network or my other device become slow too, but if i disconnect my macbook from the network, my network back normal again. I've try every methods from internet but thats not solve my problem. I think the problem is in the Airport Card and plan to replace it but I'm also not sure that it will solve the problem. Does anyone know what i should do?
Sorry my bad english
Sorry my bad english