Broken login after upgrade to 19.07.2 on GL.iNet GL-AR150

Hi,

I was using GL.iNet GL-AR150 with openwrt 18.06.4 for quite a while.
My router spans its own Wifi sub net while its WAN interface connects to another router of my telco provider.

Today I decided to upgrade to 19.07.2 and I downloaded

openwrt-19.07.2-ath79-generic-glinet_gl-ar150-squashfs-sysupgrade.bin

linked under https://openwrt.org/toh/gl.inet/gl-ar150.

For the upgrade I used the Luci web interface and kept "keep configuration" checked.

After the upgrade my wifi came back after some minutes. Strangely it now assigned me an IP address from the subnet of my telco router. Also the only other device I can reach in that sub net is my telco router. It seems that my GL.iNet GL-AR150 has no accessible IP anymore. However, routing into internet work.
Everything feels like I would be directly connected with my telco router but I am definitely connect to the Wifi of my GL.iNet GL-AR150.

Does anyone understand what happened here?
Ho can I reconnect and repair my GL.iNet GL-AR15?

Many thanks in advance

@mhproc, welcome to the community!

:man_facepalming:

Never do that between versions. I'd suggest doing a reset to defaults.