Wifi connection wont work

Hello,

I just got my raspberry pi 4 and installed umbrel. Everything worked fine I connected my Raspberry with lan. Now I want to connect is with Wifi but is doesnt work. I got via SSH on my raspberry and changed wpa_supplicant.conf like in many Youtube tutorials. Everything good so far but when I restart my raspberry and disconnect my Lan-connection it wont connect via Wifi and I dont know why.
I hope someone can help me