Usually, in real life, bickering between black Americans and African immigrants would take place in the form of some isolated incidents (Africans holding stereotypes against ADOS as being lazy, violent, rude, jealous, etc., ADOS holding stereotypes against Africans as being backwards, undeveloped, weird, silly, submissive towards whites)
But again, these were mostly isolated incidents. Most interactions were fine.
Then suddenly in the last few years, it became this big topic online, that was made worse by online losers deciding to take the bait so they could get a power trip (etc. "Africans are smarter and better than you, you're slaves!" Or "all you africans are c00ns" with some stereotypical exagerrated african names or jokes) instead of downvoting and reporting the content.
The reality is that most ADOS and most Africans don't really have any strong feelings against each other. Some adults may hold some stereotypes, but only few of them hold them strongly. For most it's not even a common subject that gets brought up.
But the issue is that the strongest vocal minority always has to project their feelings, and people who respond to it feel the need to defend their side, thus amplifying this divide.