Strange AT+NETMODE response: 8,5,0,0,0,1,2,1,0,0,5

Question

I'm getting a strange response from AT+NETMODE, which is:

+NETMODE: 8,5,0,0,1,1,2,1,0,0,5

...Is this normal? What does it mean?

Context:

I want to send SMS using a ZTE M190 SMS modem controlled by a software I made with Windev23. That modem don't say it complies with my current OS (Windows 10), but I had success sending GSM SMS (with AT+CMGF=1) for a decent number of tests with a program I made on Windev23 and also with other 3rd party software. Now I want to include UCS2 charset in the SMS. I know the basics of sending SMS, which seem to vary the encoding for PDU:

AT+CMGS=<length><CR>
<Message in PDU><ctrl+z>

But I'm still failing hard trying to understand the encoding for UCS2 SMS, so for now I used AT Command Tester to make me simple PDU messages and test the modem for PDU. I copied their hexadecimal PDU and pasted in a FooString like:

AT+CMGS=FooString

...and tried to send that command to the modem with Windev. But I get different errors and I think the bad behavior might be linked to the below diagnosis:

AT+CSQ ...returns +CSQ: 31,99 (indicates excellent to no signal)
AT+NETMODE? or AT+NETMODE=? ...returns +NETMODE: 8,5,0,0,1,1,2,1,0,0,5

I didn't find that netmode response anywhere and can't change it's response issuing command AT+NETMODE=FooNumber like AT+NETMODE=1

More diagnosis:

AT ...returns OK
AT+CMGF ...asnwers for 1 or 0 (text or PDU)
AT+CSCA="+550101102010",145 ...returns OK
AT+CSCA? ...returns the input from above correctly

Any clue would be appreciated. Thanks in advance