Unable to see the Corrupted Nexus in the fog of war at random times

Sometimes during a play session, you begin to see some of them in the fog of war, while other times they disappear. It's difficult to explore without knowing which way to go if you need them to complete the quest.

Example of a Corrupted Nexus in the fog of war that disappeared after a client restart:





And another Corrupted Nexus that I hadn't been able to see before appeared in the fog of war after the same client restart.