The SSID is not detected by iPhone SE and iPhone 7 (both support 802.11ac), and they're tested right next to the antennas.

Hi, just upgraded from WR-841ND to Archer C7, but I can't seem to detect the 5GHz network. The 2.4 shows up just fine, already enabled the radio, the LED for 5GHz is also on. What should I do?