While in the field test phase of our custom nrf9161 based device, we figured out that there are some towers of some providers that make the device seem online although it is not able to get a connection to our cloud. To mitigate that problem our workaround involves "blacklisting" a PLMN to figure out if this solves the problem.
We are using the AT Shell to provide AT Commands to the 9161. Unfortunately writing to the AT%PALL command always gives back an error. Only reading (AT%PALL=0) and deleting all entries (AT%PALL=2) seem to work. To get the device therer I updated the modem firmware to 2.0.2. What could be the problem? The failed command in question would be AT%PALL= 0,1,"26203",3
Thank you for your help in advance.
