Error migrating to MySQL

Hi to all, i migrate my database to mysql using MVD but when i try to save data from a form with "Foreign Key" it get strange behavior:

It was in MVD 5.2, and happen when try to save a combobox with a foreign key setted, it duplicated the FK, but in my form are only one combobox with that key

Not happen with SQLite Database

Thanks

EDIT: It happen with all forms with a Foreign Key