We are struggling to connect the nRF9160 board Via MQTT/ NBIoT connectivity following logs we are getting
[00:01:30.021,087] <inf> mqtt_simple: The MQTT simple sample started
[00:01:30.021,118] <inf> mqtt_simple: Disabling PSM and eDRX
[00:01:30.021,148] <err> at_cmd: Failed to send AT command (err:9)
[00:01:30.021,240] <err> at_cmd: Failed to send AT command (err:9)
[00:01:30.021,301] <err> lte_lc: Failed to disable eDRX, error: -9
[00:01:30.021,301] <inf> mqtt_simple: LTE Link Connecting...
[00:01:30.021,331] <err> at_cmd: Failed to send AT command (err:9)
[00:01:30.021,392] <err> lte_lc: Could not send AT command
[00:01:30.021,423] <err> lte_lc: Could not get current system mode, error: -9
[00:01:30.021,423] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:01:30.021,453] <inf> mqtt_simple: Retrying in 120 seconds
[00:03:30.021,514] <inf> mqtt_simple: Disabling PSM and eDRX
[00:03:30.021,575] <err> at_cmd: Failed to send AT command (err:9)
[00:03:30.021,667] <err> at_cmd: Failed to send AT command (err:9)
[00:03:30.021,728] <err> lte_lc: Failed to disable eDRX, error: -9
[00:03:30.021,728] <inf> mqtt_simple: LTE Link Connecting...
[00:03:30.021,759] <err> at_cmd: Failed to send AT command (err:9)
[00:03:30.021,850] <err> lte_lc: Could not send AT command
[00:03:30.021,850] <err> lte_lc: Could not get current system mode, error: -9
[00:03:30.021,850] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:03:30.021,850] <inf> mqtt_simple: Retrying in 120 seconds
[00:05:30.021,942] <inf> mqtt_simple: Disabling PSM and eDRX
[00:05:30.022,003] <err> at_cmd: Failed to send AT command (err:9)
[00:05:30.022,094] <err> at_cmd: Failed to send AT command (err:9)
[00:05:30.022,155] <err> lte_lc: Failed to disable eDRX, error: -9
[00:05:30.022,155] <inf> mqtt_simple: LTE Link Connecting...
[00:05:30.022,186] <err> at_cmd: Failed to send AT command (err:9)
[00:05:30.022,277] <err> lte_lc: Could not send AT command
[00:05:30.022,277] <err> lte_lc: Could not get current system mode, error: -9
[00:05:30.022,277] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:05:30.022,277] <inf> mqtt_simple: Retrying in 120 seconds
[00:07:30.022,369] <inf> mqtt_simple: Disabling PSM and eDRX
[00:07:30.022,430] <err> at_cmd: Failed to send AT command (err:9)
[00:07:30.022,521] <err> at_cmd: Failed to send AT command (err:9)
[00:07:30.022,583] <err> lte_lc: Failed to disable eDRX, error: -9
[00:07:30.022,583] <inf> mqtt_simple: LTE Link Connecting...
[00:07:30.022,613] <err> at_cmd: Failed to send AT command (err:9)
[00:07:30.022,705] <err> lte_lc: Could not send AT command
[00:07:30.022,705] <err> lte_lc: Could not get current system mode, error: -9
[00:07:30.022,705] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:07:30.022,705] <inf> mqtt_simple: Retrying in 120 seconds
[00:09:30.022,796] <inf> mqtt_simple: Disabling PSM and eDRX
[00:09:30.022,857] <err> at_cmd: Failed to send AT command (err:9)
[00:09:30.022,949] <err> at_cmd: Failed to send AT command (err:9)
[00:09:30.023,010] <err> lte_lc: Failed to disable eDRX, error: -9
[00:09:30.023,010] <inf> mqtt_simple: LTE Link Connecting...
[00:09:30.023,040] <err> at_cmd: Failed to send AT command (err:9)
[00:09:30.023,132] <err> lte_lc: Could not send AT command
[00:09:30.023,132] <err> lte_lc: Could not get current system mode, error: -9
[00:09:30.023,132] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:09:30.023,132] <inf> mqtt_simple: Retrying in 120 seconds
[00:11:30.023,223] <inf> mqtt_simple: Disabling PSM and eDRX
[00:11:30.023,284] <err> at_cmd: Failed to send AT command (err:9)
[00:11:30.023,376] <err> at_cmd: Failed to send AT command (err:9)
[00:11:30.023,437] <err> lte_lc: Failed to disable eDRX, error: -9
[00:11:30.023,437] <inf> mqtt_simple: LTE Link Connecting...
[00:11:30.023,468] <err> at_cmd: Failed to send AT command (err:9)
[00:11:30.023,559] <err> lte_lc: Could not send AT command
[00:11:30.023,559] <err> lte_lc: Could not get current system mode, error: -9
[00:11:30.023,559] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:11:30.023,559] <inf> mqtt_simple: Retrying in 120 seconds
[00:13:30.023,651] <inf> mqtt_simple: Disabling PSM and eDRX
[00:13:30.023,712] <err> at_cmd: Failed to send AT command (err:9)
[00:13:30.023,803] <err> at_cmd: Failed to send AT command (err:9)
[00:13:30.023,864] <err> lte_lc: Failed to disable eDRX, error: -9
[00:13:30.023,864] <inf> mqtt_simple: LTE Link Connecting...
[00:13:30.023,895] <err> at_cmd: Failed to send AT command (err:9)
[00:13:30.023,986] <err> lte_lc: Could not send AT command
[00:13:30.023,986] <err> lte_lc: Could not get current system mode, error: -9
[00:13:30.023,986] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:13:30.023,986] <inf> mqtt_simple: Retrying in 120 seconds
[00:15:30.024,078] <inf> mqtt_simple: Disabling PSM and eDRX
[00:15:30.024,139] <err> at_cmd: Failed to send AT command (err:9)
[00:15:30.024,230] <err> at_cmd: Failed to send AT command (err:9)
[00:15:30.024,291] <err> lte_lc: Failed to disable eDRX, error: -9
[00:15:30.024,291] <inf> mqtt_simple: LTE Link Connecting...
[00:15:30.024,322] <err> at_cmd: Failed to send AT command (err:9)
[00:15:30.024,414] <err> lte_lc: Could not send AT command
[00:15:30.024,414] <err> lte_lc: Could not get current system mode, error: -9
[00:15:30.024,414] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:15:30.024,414] <inf> mqtt_simple: Retrying in 120 seconds
[00:17:30.024,505] <inf> mqtt_simple: Disabling PSM and eDRX
[00:17:30.024,566] <err> at_cmd: Failed to send AT command (err:9)
[00:17:30.024,658] <err> at_cmd: Failed to send AT command (err:9)
[00:17:30.024,719] <err> lte_lc: Failed to disable eDRX, error: -9
[00:17:30.024,719] <inf> mqtt_simple: LTE Link Connecting...
[00:17:30.024,749] <err> at_cmd: Failed to send AT command (err:9)
[00:17:30.024,841] <err> lte_lc: Could not send AT command
[00:17:30.024,841] <err> lte_lc: Could not get current system mode, error: -9
[00:17:30.024,841] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:17:30.024,841] <inf> mqtt_simple: Retrying in 120 seconds
[00:19:30.024,932] <inf> mqtt_simple: Disabling PSM and eDRX
[00:19:30.024,993] <err> at_cmd: Failed to send AT command (err:9)
[00:19:30.025,085] <err> at_cmd: Failed to send AT command (err:9)
[00:19:30.025,146] <err> lte_lc: Failed to disable eDRX, error: -9
[00:19:30.025,146] <inf> mqtt_simple: LTE Link Connecting...
[00:19:30.025,177] <err> at_cmd: Failed to send AT command (err:9)
[00:19:30.025,268] <err> lte_lc: Could not send AT command
[00:19:30.025,268] <err> lte_lc: Could not get current system mode, error: -9
[00:19:30.025,268] <inf> mqtt_simple: Failed to establish LTE connection: -9
[00:19:30.025,268] <inf> mqtt_simple: Retrying in 120 seconds