Radio goes off by itself

Dear all,
I have an issue with radio.
At first, I switch radio on (cm radio on). After that, module registers into network, everythink is ok.
After long time, I would say one day, I see on AT interface at+csq returns always +CSQ: 99,99
and AT+CREG? returns always +CREG: 0,0.
Then I check cm radio status, I see that the power is off. The radio goes off by itself.
Why does the radio go off by itself?
How can I avoid that?
I am using WP7607-1 and legato 18.6.3.

I am not sure but It might be due to power saving which is automatically activated. I use le_pm_StayAwake() to make sure my chip won’t go into power saving mode. If its power saving then you can easily see that in the logs (logread)

I have also seen some cammands for setting power state trough AT commands