To help troubleshoot further, please share your (e.g., Windows 11, macOS Sonoma), if the modem is carrier-locked or unlocked , and the exact error message you see. Share public link
Some older revisions of the ZTE MF833T firmware struggle to communicate properly with modern USB 3.1 or USB-C ports (via adapters). If your device keeps disconnecting, plug it into a legacy USB 2.0 port (typically color-coded black or grey) or use a USB 2.0 extension cable. zte mf833t driver full