I write what you can do more but I think you should ask to support about that error because I not have that repeat-one-error at any of my r11e-lte6 modules.
Please read and install this Watch LTE parameters: http://forum.mikrotik.com/t/r11e-lte6-2ca-not-staying-connected/136004/22
If you want do some detection & action then check both:
Simple watchdog: http://forum.mikrotik.com/t/sxt-lte-4g-cat6/134468/1
Advance watchdog: http://forum.mikrotik.com/t/tx-rx-fp-rx-dropped-pppoe-account/132656/1
MAIN
In title “Modem hangs, until reset” but what reset ?
at+reset ?
usb power-reset?
lte disable and eneble ?
system reboot ?