That one was tricky. Got brand new router and couldn’t connect to 5 Ghz network. My iPhone didn’t have this issues, neither couple other devices at home. I spend some time randomly changing settings on wireless network, and then I found tricky information – my MacBook can’t use all available channels, can work only on specific one.
How to get list of available channels – just go to “
Apple” on top left corner of your screen -> About this
Mac -> System report…
and then change settings of router to work on one of Supported Channels: