If you ask for a field via relationship in a calculation FM will give you the first related record you would see in a portal.
You can change the sort order of the relationship and vary the first related record. In your case the relationship wants to be sorted by date descending.
Yes I tried that and it does not seem to have any effect.
Any other ides
Thank you for your posts.
The answer by "jensteich" is complete and correct (Thank you!).
If the portal is being sorted by the date field in descending order, the latest date should be appearing first. What date is appearing first?