Thank you for your query.
Currently it is a known issue with Internet.telekom APN. Our legacy firmware version had a different type of logic when it came to Auto APN. After you have upgraded to 7.1.2 DFOTA has most likely upgraded your modem module. Since Auto APN is directly related to the Modem module this has caused issues, since RUTOS firmware uses a different logic when it comes to Auto APN settings.
Currently, the fix could be expected with our 7.2/7.3 Firmware release, exact date is unknown yet.
However, if you have the opportunity to add the device to RMS and provide the internet connectivity via WAN to your RUT240 our Research and Development(R&D) team would connect to your device and would try troubleshooting the issue. If you would be willing to try this, please send me a private message with your device Serial Number and its password. You could change the password to Teltonika1 for testing purposes.
Instructions how to add your device to RMS: https://wiki.teltonika-networks.com/view/RMS_Device_menu#Add_device
Note: Make sure that you send the device details via private message only. Do not share any device information publicly on this forum.