Why do secondary bands show SINR=0.0 ?

Why do secondary bands always show SINR 0.0 ?

Network
LTE FDD / LTE CA Downlink
Band
LTE Band 12 (700 MHz)
RSSI: -62dBm SINR: 11.9dB RSRP: -94dBm RSRQ: -14.0dB
Secondary Band (SSC1)
LTE Band 2 (1900 MHz)
RSSI: -75dBm SINR: 0.0dB RSRP: -93dBm RSRQ: -3.0dB
Secondary Band (SSC2)
LTE Band 2 (1900 MHz)
RSSI: -77dBm SINR: 0.0dB RSRP: -95dBm RSRQ: -4.0dB
Secondary Band (SSC3)
LTE Band 66 (AWS 1700/2100 MHz)
RSSI: -80dBm SINR: 0.0dB RSRP: -99dBm RSRQ: -3.0dB

Network
LTE FDD / LTE CA Downlink
Band
LTE Band 2 (1900 MHz)
RSSI: -67dBm SINR: 15.2dB RSRP: -93dBm RSRQ: -11.0dB
Secondary Band (SSC1)
LTE Band 2 (1900 MHz)
RSSI: -77dBm SINR: 0.0dB RSRP: -94dBm RSRQ: -3.0dB
Secondary Band (SSC2)
LTE Band 66 (AWS 1700/2100 MHz)
RSSI: -62dBm SINR: 0.0dB RSRP: -92dBm RSRQ: -13.0dB

Network
LTE FDD / LTE CA Downlink
Band
LTE Band 66 (AWS 1700/2100 MHz)
RSSI: -70dBm SINR: 13.9dB RSRP: -98dBm RSRQ: -10.0dB
Secondary Band (SSC1)
LTE Band 2 (1900 MHz)
RSSI: -59dBm SINR: 0.0dB RSRP: -90dBm RSRQ: -14.0dB
Secondary Band (SSC2)
LTE Band 2 (1900 MHz)
RSSI: -75dBm SINR: 0.0dB RSRP: -96dBm RSRQ: -7.0dB