After WIFI setup with static IP, no connecltion without LAN cable

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I just setup a completely new RPI3+ HassOS instance. Only SSH & Web terminal add-on was installed.
After boot up, I can connect perfectly via LAN cable.
After setup WIFI connection and static IP address and reboot, I can connect via LAN calbe and also via WIFI.
I used this guide: Guide: Connecting Pi with Home Assistant OS to wifi (or other networking changes)

If I disconnect LAN cable, it is stop communication on WIFI as well. Not possible to connect via WIFI. Even if I set up DNS and GATEWAY (my router is using 192.168.1.1).

USB stick and my-network file setup method is not working at all for me. Does nothing.

Any idea or suggestion?

Check the wifi and Ethernet profiles you’ve made. Look at the IP addresses for both. Are they the same?

Still not working after reading through a hell of a lot of things.
I do not know how to check the profile for ethernet and wifi…
IP addresses are different of course.

So, how to check the profiles?
Also, what do I have to check?
What should I look for?