China Mobile NB-IoT connection issue on Band 5

[AlbertSerica]

Hello, I've tested multiple NB-IoT cards from China Mobile using the asset tracker on nRF9160 DK. The NB on Band 8 (AT%XCBAND returns %XCBAND: 8) has no issue connecting to nrf Connect to Cloud, but NB on Band 5 got stuck on LED 3 blinking. Is there anything I could do to get Band 5 working?

[AlbertSerica]

I contacted China Mobile and it seems that they turn off power-saving function to solve this problem. After that, the band 5 switched to band 8.