Final Boss drops x Scarabs and additional final bosses

If you click an altar that has the final boss drops x scarabs mod, added bosses such as the ones from the pandemonium scarab or the domination scarab of terrors will NOT also drop those scarabs. The actual boss of the map DOES drop the scarabs. As far as I can tell, currency and div cards work on the added final bosses, it's just scarab drops that aren't working.