WiFi only works when eth is on

Troubleshooting
1

I have weird problen with Neo board and dietpi 8.4.2.

I setup wifi via dietpi-config, but one always says that is disconnected, I can run ifup wlan0 and it works.

In my router I see two ip adderesses, but if I disconnect eth both connection doesn’t work.
If I disable eth in dietpi-config I can’t connect anymore.

How can I configure wifi?

  1. I can’t access /boot after flashing (windows doesn’t recognise file system)
  2. I can’t setup wifi via dietpi-config