Dude, this happens because k8 series doesn't support dual 4G at same time in both sim slots. We haven't received any update for this.
This issue can be resolved only if Lenovo release OTA update for dual 4G for k8 series.
This is not possible Lenovo never do this.
Lenovo is committed to environmental leadership from operations to product design and recycling solutions.
See our Sustainability Report.