This is going to be a very interesting problem here at my job.

Of course I fixed it (for that particular table), but just had a conversation with one of the Developers and he was firm in saying that no one manually lower the seed value (reseed) or increased the actually ID on that column, I guess using IDENTITY INSERT somewhere in the INSERT code? And I truly believe him. Same way that I explained to him I have not reseed those values myself.

Very coincidental that this is happening only on the SQL 2012 instance and never happened before though.

I honestly can't remember of any other way to make these two values different than using DBCC CHECKIDENT or manually forcing and changing the upper existing value on that column.