I think that may be down to a couple things, the American flag is synonymous with white supremacy, the Jamaican flag not quite, people have to remember that Jamaica is a country that is 95% black, the dynamics therefore are more akin to certain African countries, so I think that’s where some of the perceived raised eyebrows come from.
Also when people go to foreign lands they draw back to something of where they came from, if for example a wave of Black Americans were to emigrate to a foreign land you’d see more of these people play up their ‘Americaness’ in this foreign land and they wouldn’t be wrong, this is what immigrants do.
And I was talking more about the black women comment in regards to John Boyega, he implicitly said he preferred black women mostly and only, I haven’t seen an actor be so brazen with his blackness since Denzel and his whole comments about not kissing Julia Roberts because it might alienate his black female fanbase.