using Marathon, I have unchecked the NOT NULL property of column XY.

If I list the table structure, now XY appears as a nullable (not NOT
NULL) column.

However, if I try to input a NULL value, I get an error message,
exactly as FB retained the NOT NULL property for the column.

Is there a safe and easy way to fix things ?

I have a large number of dependencies on that column ...

TIA

Duilio Foschi