If you use the /etc/opkg/openwrt/distfeeds.conf configuration file for opkg, you are installing packages from repositories other than Teltonika’s. These packages have not been thoroughly tested with our devices, so they may not work properly. For packages that have been tested and are guaranteed to work, please use the /etc/opkg/openwrt/teltonikafeeds.conf feeds file.
Thanks for your response. Unfortunately, tmux is no longer available for installation using etc/opkg/openwrt/teltonikafeeds.conf. While this package worked fine with firmware version 7.4, it is not functioning with version 7.7.