After some months I upgraded LTE moden FW and mikrotik to 6.45.9 and SXT LTE1 interface started freezing again. Any idea, what is state 11?

RBSXTR is something what I would definitelly not recomanded for LTE connection!

few time is day error message:
Jul/05/2020 14:07:38 lte,info lte1: not registred, state: 11
Jul/05/2020 14:07:38 interface,info lte1 link down

only hard restart helps - removing from power.
Script with disable lte1 and enable lte1 doesnt help ...

What modem firmware you have?
Enable in logs topics=lte,!raw

What modem firmware you have?
Enable in logs topics=lte,!raw

MikroTik_CP_2.160.000_v017

I just schedule restart every 24h and it doesnt happend until now again. But will be better if it works without restarts. Thank for log. I didnt know how to filter that LTE info flood

Finally i got more logs. Seems like its happening same as before. Mikrotik doest see SIM, restart doesnt help. just remove SIM and plug it back and that it works. I tryed both ports and replace SIM card also and still same. SIM has no pin. Trying to downgrade to STABLE 6.46.6 - this worked without problem for 6 monts ...

Jul/25/2020 09:44:03 lte,async,event +MSTK: 14
Jul/25/2020 09:44:03 lte,async,event +CPIN: READY
Jul/25/2020 09:44:03 lte,async,event ^SIMST: 1
Jul/25/2020 10:05:09 lte,async,event +CPIN: SIM REMOVED
Jul/25/2020 10:05:09 lte,async,event ^CARDMODE: 255
Jul/25/2020 10:05:09 lte,async,event ^SIMST: 255,0
Jul/25/2020 10:05:09 lte,async,event +MPBK: 0
Jul/25/2020 10:05:09 lte,info lte1: not registred, state: 11
Jul/25/2020 10:05:09 lte,async,event +MMSG: 1, 0
Jul/25/2020 10:05:09 lte,async,event +CGEV: ME DETACH
Jul/25/2020 10:05:09 lte,account lte1 session: 21840s 14518808/11081297 bytes 78442/57018 packets
Jul/25/2020 10:05:09 lte,async,event +CGEV: EPS PDN DEACT 5
Jul/25/2020 10:05:09 interface,info lte1 link down
Jul/25/2020 10:05:09 lte,async,event +CGEV: ME DETACH
Jul/25/2020 10:06:16 lte,async,event +CGEV: ME DETACH
Jul/25/2020 10:06:16 lte,async lte1: rcvd OK
Jul/25/2020 10:06:16 lte,async lte1: sent AT+EEMOPT=1
Jul/25/2020 10:06:16 lte,async lte1: rcvd OK
Jul/25/2020 10:06:16 lte,async lte1: sent AT*MRD_SN?
Jul/25/2020 10:06:17 lte,async lte1: rcvd *MRD_SN:xxx
Jul/25/2020 10:06:17 lte,debug lte serial: *MRD_SN:xxx
Jul/25/2020 10:06:17 lte,async lte1: sent AT+CFUN=4
Jul/25/2020 10:06:17 lte,async lte1: rcvd OK
Jul/25/2020 10:06:17 lte,async lte1: sent AT*CGDFLT=0,"IP","internet",,,,,,,,,,1,0,,,,,,,1
Jul/25/2020 10:06:17 lte,async lte1: rcvd OK
Jul/25/2020 10:06:17 lte,async lte1: sent AT*CGDFAUTH=0,0
Jul/25/2020 10:06:17 lte,async lte1: rcvd OK
Jul/25/2020 10:06:17 lte,async lte1: sent AT+CPIN?
Jul/25/2020 10:06:17 lte,async lte1: rcvd +CME ERROR: SIM not inserted
Jul/25/2020 10:06:19 lte,async lte1: sent AT+CPIN?
Jul/25/2020 10:06:19 lte,async lte1: rcvd +CME ERROR: SIM not inserted
Jul/25/2020 10:06:21 lte,async lte1: sent AT+CPIN?
Jul/25/2020 10:06:21 lte,async lte1: rcvd +CME ERROR: SIM not inserted
Jul/25/2020 10:06:23 lte,async lte1: sent AT+CPIN?
Jul/25/2020 10:06:23 lte,async lte1: rcvd +CME ERROR: SIM not inserted

Write to support@mikrotik.com with that logs !