i've tried downgrading both the node as well as the router
the node works fine and is downgraded to the october firmware
after that i tried downgrading the router.. within seconds its showing that the upgrade was unsuccessful.
Same issue here since the 3.0.0.4.386_41535 version
reported the issue via the feedback function.
As per today it looks like the new firmware is not available anymore on the asus website.