Ughh, I feel your pain on this one Larathiel, and first-hand at that. I have spent a lot of time calling attention to broken Journey Steps. Because I view them as the closest thing we have to a main questline, it really bothers me if they are not working. Although I begrudgingly turn a blind eye to the Mummy of the Ring, as he is coming content, Explore the entire Exiled Lands shall recieve no such free pass. I am re-testing the offending step using an alternate map this weekend, and if I still cant get it to pop, I will make a full bug report. Dont worry, now that I have it in my sights, Im going to start pressing Funcom a lot more for a fix for this.
Pretty much everything you have just said is correct Sera. For any who are interested, you can spawn in and battle the Mummy of the Ring and battle him now. I am happy to provide his spawn in id for anyone who would like it. However, a WARNING: he feels very weak and unfinished in his current state, like a mere prototype they are building on. He literally only has a few thousand hp; less than most bosses. And killing him with either a weapon or Admin commands will log the Step as completed. You are probably better to simply wait for his official release.
Myself and another member with a DevKit discuss these two steps in greater detail in the below thread.