I am using the Xiaomi AX3000T (RD03, early version) with OpenWRT for several months and it all worked just fine.
Until I had the great idea to upgrade to the latest version.
I had set it up as an AP.
Before upgrading I downloaded the config and checked the box to keep the settings.
I have already reset the device by holding the reset button and plugged in the powerplug, but the light turns blue and the device is up and running, but without wifi channels and the ability to connect to the device.
wifi off is fine post reset, it's disabled by default, you'll need an ethernet cable.
it also means it doesn't appear to be bricked, since reset worked.
how is the device connected to the upstream router ?
Ah, a reset gave me the option to ping the device and the mainrouter (wired connection) sees the device as OpenWrt instead of OpenWrt.localdomain, with same IP address.
Well, I disconnected the router from my mainrouter and connected to the AX3000T directly. Then I got an IP, went to 192.168.1.1 through putty and logged in as root, finally getting into the router! Tnx!
What is wise to do next? upgrading the firmware to the latest through the console?
with the default config, this will only work if you use the WAN port to connect to the upstream router.
hard to know without an error message, but I'm guessing you're hitting the scp error described in the 2nd troubleshooting section of the sysupgrade.cli link, it applies to winscp too.