You’re correct. Anyway, as Wikipedia says:
“Black Hebrew Israelites (also Black Hebrews, African Hebrew Israelites, and Hebrew Israelites) are groups of people mostly of Black African ancestry situated mainly in the United States who believe they are descendants of the ancient Israelites. Black Hebrews adhere in varying degrees to the religious beliefs and practices of mainstream Judaism. They are generally not accepted as Jews by the greater Jewish community, and many Black Hebrews consider themselves — and not mainstream Jews — to be the only authentic Jews. Many choose to self-identify as Hebrew Israelites or Black Hebrews rather than as Jews.”
That’s as good of a summary as I could give. These people are of no connection to the genuine Ethopian Jews; they frequently profess anti-Semitism, in fact, and afro-centrist views similar to the bullshit artists who claim every historical figure to be black. Moses was black, Jesus was black, Shakespeare was black, Beethoven was black, everyone was black. I have very little patience for people who try to falsely appropriate someone else’s history as their own.
You will of course find American blacks who have actually converted to Judaism and belong to Jewish synagogues; these people are genuine Jews and are accepted and welcomed as such by the rest of the Jewish community. Julius Lester is one example, though he was also partially Jewish by birth, and he was not raised with any kind of Jewish identity whatsoever. There are plenty of genuine black Jews, both of African-American and of Ethiopian descent, but the “Black Hebrews” are as representative of actual Judaism as the Nation of Islam is of genuine Islam.