AD7091-4 internal oscillator

Hello

My customers are suffering from 124MHz and 63MHz unwanted radiation appearing on the board.
My customers are exhaustively checking the device's internal oscillator on the board.
If you have any material that reassures my customers about the AD7091R-4, please let me know.
Of course, if you know the cure, please tell me.
I just advised my customer to scan the board with an electromagnetic field probe.

Best regards