One table in a file 'System' has a field 'WorkingYear'

A file/table Contracts uses 3 fields to get acces via a relation to a
table with Appointments.
One of these fields is a calculated field, it contains a copy of
'System::WorkingYear'

A layout in the file for the contracts, for records of a table in
another file 'Docents' contains references to the Contracts.

When the System::WorkingYear field is changed, the copy in the
Contracts file is updated accordingly,
but the relation from Contracts to Appointments is not updated.

All the calculation fields are unstored.

What rule in the FM documentation did I miss?

So I am looking to related records, with 1 TO inbetween, and the
inbetween TO uses a calculated field in the final relation.
Changing the target of the calculated field does not update the set
of related records.

(FM 8 on Windows)