Foreign key being deleted

Hi,

I found a strange behavior in Transaction Replication. After the synchronization, one of my foreign keys is being deleted.

That situation happens with the follow sample:

CREATE TABLE [dbo].[Table1] (
    [ColumnA] BIGINT NOT NULL,
    [ColumnB] BIGINT NOT NULL,
    [ColumnC] INT    CONSTRAINT [DF_Table1_ColumnB] DEFAULT ((0)) NOT NULL,
    CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED ([ColumnA] ASC)
);
GO

CREATE UNIQUE NONCLUSTERED INDEX [UQ_Table1_ColumnC_ColumnB]
    ON [dbo].[Table1]([ColumnC] ASC, [ColumnB] ASC)
    INCLUDE([ColumnA]);
GO


CREATE TABLE [dbo].[Table2] (
    [ColumnX] INT    IDENTITY (1, 1) NOT FOR REPLICATION NOT NULL, --Subscriber: [ColumnX] INT    NOT NULL,
    [ColumnY] BIGINT NOT NULL,
    [ColumnZ] INT    NOT NULL,
    CONSTRAINT [PK_Table2] PRIMARY KEY CLUSTERED ([ColumnX] ASC),
    CONSTRAINT [FK_Table2_Table1] FOREIGN KEY ([ColumnZ], [ColumnY]) REFERENCES [dbo].[Table1] ([ColumnC], [ColumnB])
);
GO

The foreign key being deleted is FK_Table2_Table1.

Did anyone experience something similar? If yes, what's the reason?

Thanks.