This strikes me as shameful behavior.

You should say the truth: you're an American, and Americans have a diversity of views on most subjects, just like every other country.

When conducting business this is more trouble, and causes more discomfort, than it’s worth.

FWIW, I've dozens of backpackers around the world with Canadian flags sewn on their backpacks who later admit quietly they're American.

They said it just makes life easier while travelling.

I used to be proud of our flag and would display it. Now (past 3 years) it has morphed into a symbol of hate and oppression. When I see armed 'protestors' terrorizing a state legislature and waving the flag, then the flag is no longer a symbol of freedom but of intimidation.

You may want to read the history of banana republics. https://en.wikipedia.org/wiki/Banana_republic.

Given the wildness of that particular dark corner of our history, I'm looking forward to reading about the history we're living through now. Hopefully after some emotional remove, like in another ten years.