nanoframework esp32 wifi connection fails

I am trying to connect to wifi using esp32 nanoframework. Have tried various samples, for example: https://github.com/nanoframework/Samples/blob/main/samples/Wifi/ScanWiFi/Program.cs

I am getting the below exception on this line:

WifiAdapter wifi = WifiAdapter.FindAllAdapters()[0];

Exception:

Starting Wifi scan
    ++++ Exception System.InvalidOperationException - CLR_E_INVALID_OPERATION (1) ++++
    ++++ Message: 
    ++++ System.Device.Wifi.WifiAdapter::NativeScanAsync [IP: 0000] ++++
    ++++ System.Device.Wifi.WifiAdapter::ScanAsync [IP: 000d] ++++
Exception thrown: 'System.InvalidOperationException' in System.Device.Wifi.dll
message:Exception was thrown: System.InvalidOperationException
stack:System.Device.Wifi.WifiAdapter::NativeScanAsync
System.Device.Wifi.WifiAdapter::ScanAsync

I have tried various things such as

reboot device
manually enter network config, set enabled etc.
reflash

Solution

So looks like it was an issue to do with the same SSID on 5GHz as I had on 2.4GHz.

Things I looked at that weren't actually necessary to get it working

special config for the router. What I had by default for GW, DHCP, NTP etc. was all fine.
special network config in VS for the device. The "automatic" settings actually all work and the code samples work well too. e.g. : https://github.com/nanoframework/Samples/tree/main/samples/SSL/SecureClient_WiFi

The only thing was that the esp should connect to the SSID on 2.4GHz and not the same one on 5GHz.