Sequelize: "Model has not been defined" when relationship across multiple databases

I'm trying to instanciate one sequelize per Database. Some tables in DB1 has relationships with tables in DB2, and reverse. One of the relationships is DB1.Utilisateur.contenuProvenance_id => DB2.Contenu.id and DB2.Contenu.utilisateur_id => DB1.Utilisateur.id.

Here is the Utilisateur model:

@Table
export default class Utilisateur extends Model<Utilisateur> {

    @API() @PrimaryKey @AutoIncrement @Column({ type: DataType.INTEGER })
    public id!: number;

    @Column({ type: DataType.STRING, allowNull: false })
    public email!: string;

    @Column({ type: DataType.STRING, allowNull: false })
    public nom!: string;

    @ForeignKey(() => Utilisateur)
    @Column({ type: DataType.INTEGER, allowNull: true })
    public parrain_id?: number;

    @ForeignKey(() => Contenu)
    @Column({ type: DataType.INTEGER, allowNull: true })
    public contenuProvenance_id?: number;
}

(Yes i'm using sequelize-typescript to declare my models as Typescript classes)

And here is how my Sequelize instance are created:

let DBs = {};
for (const ZONE of zones)
    DBs[ ZONE.name ] = new Sequelize(ZONE.serveur.bdd.nom, ZONE.serveur.bdd.login, ZONE.serveur.bdd.mdp, {
        host: ZONE.serveur.bdd.hote,
        dialect: "mariadb",
        ...
        models: ZONE.modeles // Array of models
    });

The problem: when the first instance (DB1) is created, sequelize don't find the Content table and gives me this error:

Error: Contenu has not been defined
    at Sequelize.model (project/node_modules/sequelize/lib/sequelize.js:443:13)
    at Sequelize.model (project/node_modules/sequelize-typescript/dist/sequelize/sequelize/sequelize.js:29:26)
    at project/node_modules/sequelize-typescript/dist/sequelize/sequelize/sequelize.js:51:46
    at Array.forEach (<anonymous>)
    at project/node_modules/sequelize-typescript/dist/sequelize/sequelize/sequelize.js:49:26
    at Array.forEach (<anonymous>)
    at Sequelize.associateModels (project/node_modules/sequelize-typescript/dist/sequelize/sequelize/sequelize.js:45:16)
    at Sequelize.addModels (project/node_modules/sequelize-typescript/dist/sequelize/sequelize/sequelize.js:37:14)
    at new Sequelize (project/node_modules/sequelize-typescript/dist/sequelize/sequelize/sequelize.js:19:22)

Is it possible to create the sequelize instances one by one, although there are relations between databases ?

Should I add models after all sequelize instances has been created ?

Thanks for your help guys

Related:

• SequelizeJS: How to include association (join) across multiple databases without using raw query

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