EG912Y impossible to set the format of the short messages to TEXT mode when CMUX is enabled


After I have updated the module EG912Y from version EG912YEUAAR01A08M16 to the version EG912YEUAAR01A11M16 I find a problem with the command at+cmgf=1 when the CMUX is enabled.
It seems that it’s impossible to set the format of the short messages to TEXT mode.

Please, see the file attached.

My comment:

at line 109 CMUX started:
[2021-12-29 14:09:29.322] AT+CMUX=0,0,5,1500,10,3,30,10,2

at line 139 I set SMS text mode (on CMUX channel 1)
[2021-12-29 14:09:29.460] AT+CMGF=1
[2021-12-29 14:09:29.472]
[2021-12-29 14:09:29.472] MDM1(GSM):[RX]
[2021-12-29 14:09:29.472] OK

at line 212 I check the state of CMGF and it is 0=PDU (Why???)

[2021-12-29 14:09:30.137] AT+CMGF?
[2021-12-29 14:09:30.148]
[2021-12-29 14:09:30.148] MDM1(GSM):[RX]
[2021-12-29 14:09:30.148] +CMGF: 0
[2021-12-29 14:09:30.148]
[2021-12-29 14:09:30.148] OK

at line 231 the command AT+CMGL=“ALL” fails… i think because SMS is not set as text mode

[2021-12-29 14:09:30.171] AT+CMGL=“ALL”
[2021-12-29 14:09:30.202]
[2021-12-29 14:09:30.202] MDM1(GSM):[RX]
[2021-12-29 14:09:30.202] +CMS ERROR: operation not allowed
[2021-12-29 14:09:30.202]

What can I check?

Thank you,
Stefano (1.5 KB)

Why would you want to use the CMUX feature? Will there be a problem with sending text messages without this feature?

I want/need to use the CMUX because my application needs of 3 connections at the same time (one TCP, one UDP, and a FTP client),
Now, I want to downgrade the fw to the version EG912YEUAAR01A08M16.
Where can I find the previous fw (EG912YEUAAR01A08M16) version? can I downgrade the firmware ?
Thank you,