Hi When I connect to Wi-Fi through my phone, I don't have internet for 40 seconds, but after this time, it connects easily and there is no problem,This situation occurs when I have not used the phone

It's been a while since I can't find the 5 GHz band, and I've tried everything from factory reset to separating Wi-Fi bands in the modem settings but the 2.4 ghz band is show in my wirless list and i