Hello,
Thank you for your question.
Could you first of all make sure of what profile the device is currently in, then see if the GPRS parameters for APN/APN Login/APN password are correct in all the profiles. If you encountering issues of switching profiles see what I/O elements control the profile change. If the GPRS settings are correct in all profiles the device should have a GPRS status: 1.
Make sure that that server and data sending settings are correctly configured in #3 profile, the device may go to this profile after reset. This would be the cause of your issue.
We would advise using profile 3 as it "default profile", set up the configuration there instead of profile 4.
See if it helps.
Regards, Teltonika Support.