Log in to the web interface and check the dashboard. For example, stable UK legacy builds for this hardware generation often use versions like 4.7.5.1.83.289 . If your firmware version date is years out of date, your device may be stuck on an old software branch.
The unit relies on passive ventilation, which can be insufficient if the unit is placed in an enclosed space. sagemcom cs 50001 firmware hot
Users have reported success calling technical support (611 for T-Mobile) and requesting they "push the new firmware" (e.g., versions like or newer) to address constant rebooting and heat issues. Log in to the web interface and check the dashboard