Forgot to answer your question.

The only podcast I know of is 'History of South Africa Podcast'.

I regularly watch 'The Lost History Files' on YouTube. It contains some good deep research into specific topics.

I don't know of anything that covers the whole Southern Africa. Probably since that is more than two times the size of the EU. You may find material if you look in the local dialect spoken in the land. German for Namibia, Portuguese for Mozambique etc.

I can recommend that you watch the interview by William F. Buckley Jr. of John Vorster. He lays out pretty nicely the conundrum they were facing.

But for a broader understanding you should read Thomas Sowell's Trilogy: 'Conquests and Cultures', 'Migrations and Cultures' and 'Race and Culture'. Thomas Sowell is just a gem.