Hello, Leon!
Please tell me what specific type of connection you are trying to establish?
Can I also ask what devices you are trying to connect to RUT955?
It is necessary to check the connection of both routers to the Internet. Try ping 8.8.8.8 on both devices. On Teltonika devices, this can be done by going to WebUI -> System -> Administration -> Diagnostics
If there is no internet connection to one of the parties, you need to check the settings of the mobile network in accordance with this article:
https://wiki.teltonika.lt/view/RUT955_Mobile#Mobile_Configuration
Also try restarting the modem.
If these initial steps do not help, please write and, if possible, send a troubleshoot file to the PM, so that I can help you figure it out.
Troubleshoot file can be downloaded via WebUI -> System -> Administration -> Troubleshoot.
Sincerely, Aliaksandr.