M35 Firmware Upgrade and USSD issue


I have a couple M35 modules inside a unit. They are on different revisions. When I try to execute a USSD command on modules with the revision: M35AR01A30 it works fine, but whenever I do the same command on: M35AR01A36 it gives me the following error:
+CUSD: 4


I’ve tried all possible ways to send the USSD command but all give this error. So I assume its a bug in the M35AR01A36 revision. Is there some way to downgrade these to M35AR01A30?

Thanks in advance!

yes, you can downgrade the firmware to M35AR01A30 via QFlash tool. You can email to support@quectel.com to get the firmware package and QFlash tool. Thanks!