Back from Wifi to LAN

Hello, please excuse my beginner question. I have built my node with wifi connection. Unfortunately this connection is not stable. Therefore I have now connected my Node with LAN. But my Node always connects nir with WLAN. Do I have to reflash my SD card, then without WPAßConfigfile? Or can I change this somewhere in the settings on the interface. How do I get the current operating system? Do I lose my channels and seeds when flashing? Thanks for your help.

Please follow this guide how to set a static IP for your node
https://community.getumbrel.com/t/how-to-set-a-static-ip-for-your-umbrel-machine/

Not really, just for setup the IP is not necessary.
Anyways, mSD card can be reflashed anytime, there’s nothing to worry about doing that. Is just the OS on it, no user data, LN data. All user data is on the SSD drive.