GL-AR150 eth0 do not works anymore

I have a GL.iNet GL-AR150-Ext/Developer Kit (PoE Version)
I was really happy, but suddendly eth0 used for WAN ceased to work, I tried several options, upgrade and downgrade firmware with no luck

actually I’m using the old FW version, 2.17 on advanced options, interface eth0 is shown as:

offline, so the same as wan, mwan tethering and modem from MWAN interface live status

what i shall do ?
i could buy another one, but if fails so easily I’d like to find another product, any suggestion?

Did you try the uboot?

yes with no luck, I bought now a 750 travel model, let’s see how it goes, hopefully will not get broken also this one