Death on Corruption Nexus removes corruption boss modifier

Found an area of corruption and travelled to the Nexus to fight the corruption boss. Was killed on the map before doing this and the Corruption Nexus boss node was removed (along with the others).

Would expect the boss node to remain, even after a map fail, so that the surrounding area can be cleansed.

I've experienced this twice now; died on a map with a normal map boss prior to defeating it, removing the corrupted nexus modifier.