I will test it again, and I send the feedback here.
It occurs when, with the plugin active, I try to get the quotes from USPS, using each of the 3 plugins I mentioned above, I received this message.
I tried with all plugins(USPS plugin, Elex WooCommerce USPS, and third-party integration) using one each time, to confirm the problem wasn’t with the plugins.
And when I disable Woocommerce Blocks and change the cart page to the regular one, it worked.
So the problem originates, in my point of view, receiving the quotes, because the same issue occurs on the checkout page.
