USB problem - K3765 Huawei with 433UAH

Hi,

I installed K3765 with ROS 4.6, everytime works perfectly, but after time (sometimes 1 day, sometimes 1 week) I cant reach router over 3G, when I connect locally, I see this errors (see picture). Nothing helps - reboot router, power off / power on. Everything is repaired when I plug out and back plug in USB with modem - modem is connected in few seconds … Could anyone help me ?
chyba%20modem%20thermoservis.jpg