The EC-25 is integrated in a linux chipsee panel PC and my sim card can register to all networks. After startup the simcard follows the following steps
4G Allowed to use data on network
GSM Attached GSM connection on network
4G Attached data connection on network
When there is a network outage the 4G detaches from the network
4G Detached data connection on network
After the network is operational again the EC-25 needs a hard power-off to restart and setup the data connection
All AT commands in a script like below do not get the data connection back alive
AT+CREG=1;+CEREG=1
AT+COPS=0
AT+CGDCONT=1,“IP”,“onomondo”
AT+CGACT=1,1
AT+QPING=1,“8.8.8.8”,5,5
After all this fails, the only way to restart the connection is by a power down of the chipsee panel pc. sudo reboot does not restart the EC-25 and the data connection