8K pro SquareDivision NOT work

Hi,
we are using 8K pro to output video, format: 4320P50 10bit. SDK 12.1.
profile bmdProfileOneSubDeviceHalfDuplex is activated.
p_config->SetFlag(bmdDeckLinkConfigQuadLinkSDIVideoOutputSquareDivisionSplit, 1) is done successfully, but the output is still 2SI, any suggestion?
Best Regards,
Peter Peng
we are using 8K pro to output video, format: 4320P50 10bit. SDK 12.1.
profile bmdProfileOneSubDeviceHalfDuplex is activated.
p_config->SetFlag(bmdDeckLinkConfigQuadLinkSDIVideoOutputSquareDivisionSplit, 1) is done successfully, but the output is still 2SI, any suggestion?
Best Regards,
Peter Peng