thank you for your answer. Nothing related to that.
In fact, there is a join error: 50% Xojo (who let me code it) and 50% me (who coded yesterday with bad glasses).
The answer was in my way to add a MenuItem, a way who works at 50% but who is wrong. In (for) the save part of the feature, I added a MenuItem SubClass and that worked fine, good, correctly, and so on.
Once at home, I took the correct glasses, get an eye on the Add MenuItems from the first part and saw that MenuItem SubClass. Once I use the same kind of code, the newly added code worked like a charm !