Connection to public and private APN

I have a SIM which supports 2 APNs, one public and one private, by configuring it with the command ‘AT+QICSGP =1,1,“private apn”,"","",3’ and then opening the TCP connection ‘AT+QIOPEN =1,0,“TCP”,“Private IP”,9191,0,1’ the connection is established.

But when adding the credentials to the public APN the connection is not created, the command responds OK with ‘AT+QICSGP =1,1,“public apn”,"","",3’ but when sending the command ‘AT+QIOPEN =1,0,“TCP”,“Public IP”,9191,0,1’ the answer is ‘+QIOPEN:0,566’

My question is if there will be any other configuration? to establish a GPRS connection when one SIM supports 2 APNs.

I am using an EC25-MX quectel modem, the model is EC25MXGAR08A02M1G

Thank you

Hello Antonio_Hernandez, thanks for your question on quectel forums
Our module support support multiple dialing, even you use private apn and public apn, it should be work well.
+QIOPEN:0,566 means socket connect fail, you should check your network registration status and whether the server turn on normally, you can use module as server to do your test., thank you.