Chosen Solution
I’ve tried rebooting, resetting, and disconnecting power for 3 minutes and reconnecting, downgrading the firmware and upgrading back to current: nothing brings back the wireless 5G. Is this something that can be repaired?
So I talked with apple support, after walking through settings in Airport Utility, it was discovered the 5Ghz network name was deleted or broadcasting as the same name as the 2Ghz (which won’t work). After re-adding a 5Ghz name, it’s broadcasting as normal. This can be found under the Airport Utility -> Device -> Edit -> Advanced -> Wifi settings -> 5GHz Name. https://support.apple.com/airport/repair…
Your AirPort only offers WiFi 802.11 a/b/g/n/ac compatibility. It does allow 2.4 GHz and 5 GHz band access simultaneously 5G is a term for cellar transmissions which your WiFi Router does not offer. Here’s a useful reference: Different Wi-Fi Protocols and Data Rates
