The GSM failed to register warning can fill the log output in cases where the modem is struggling to register, in such cases the modem tends to move from enabled->searching->enabled in a loop for an extended period. As the failed to register warning prints anytime the modem moves into enabled this can spam the log output. The fix here could be to create a short period fiber when the modem hits enabled state that waits a set amount of time for the modem to register and if it fails then log the warning.