Birth and Death years on the HTML tree appear only occationallyh

The birth and death years sometimes appears and sometimes does not.  Seems that there is no logic.  E.g. my and my father's years do, but not my mothers even if all the information is fed it.  There is also a similar post earlier without any anser.  Is this just a problem, which cannot be solved.  Not good, if so.  Example copies here:


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