No, it’s not illegal to display the U.S. flag upside down
The U.S. flag code says American flags should not be displayed upside-down except as a signal of “dire distress,” but free ...
State Department blocks pride, BLM flags from embassies, outposts with 'one flag policy'
The U.S. State Department reportedly adopted a new policy under the Trump administration that blocks U.S. embassies and outposts from flying Pride and Black Lives Matter flags.