CUSD response bug

IoT Modules GSM Module
1

Modem: Quectel M26 , M26FAR03A06_TTS
On some SIM cards i start receiving same response for different USDC requests.
Here is example:

Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*161#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 1,"Vash nomer:380XXXXXXXXX 
Vash taryf:Potuzhnyy za 100grn/ 4 tyzhni
1.Detali
2.Pereviryty datu aktyvatsiyi
3.Zavantazhuyte BiP
",15

OK

+CUSD: 4
Set device character set to GSM
AT+CSCS="GSM"

OK
AT+CUSD=1,"*121#",15

+CUSD: 2,"800hv na vsi mobil'ni nomery, rezervnyy bezlimit na lifecell, 50 GB. Nastupna oplata paketu poslug 20.02.24. Nomer diye do 22.01.25.

",15

OK

Here is explanation
For

AT+CUSD=1,"*161#",15

correct response is

+CUSD: 1,"Vash nomer:380XXXXXXXXX .....

for

AT+CUSD=1,"*121#",15

correct response is

+CUSD: 2,"800hv na vsi mobil'ni nomery, rezervnyy bezlimit na life.......

But how you can see in logs, many times for *121# i receiving response for *161#, how i can fix it?

2

Are you making sure the USSD session is closed before issuing the next

AT+CUSD=1,"*121#",15

command?

You can close a session with AT+CUSD=2

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