Xiaomi Mi Router 4A Gigabit Edition (R4AG/R4A Gigabit) -- fully supported and flashable with OpenWRTInvasion

OK, before this broke, did you make a note from the oem webui what firmware it was running orginally? you need that correct version otherwise it wont take the recovery process, also you need firmware upgrade only not the full update version

So, at this point the only way forward is to use the ch341 programmer method to extract the rom image, and hexedit to allow the uart_en=1 boot_wait=on bootdelay=5

As discussed here - Xiaomi WiFi Router 3G V2

You can then install my firmware version afterwards