I have noted that the relationship tab and some other tabs are missing on some profiles of deceased persons. These profiles have in common that they are outside of my family group, but are administered by people in my family group. I have full access to all the tabs for living profiles in this category. I discovered this phenomena by coincidence when I changed a living to deceased. Then, the tabs disappeared. Later, I did the opposite for an other profile, and the opposite happened.
The first time I discovered this was when I changed the following profile to deceased: https://www.geni.com/people/Dagfinn-Mjåseth/6000000037453596914
I believe that this is a bug, and I hope it can be fixed.