If you think your landline has become unprotected, first you should try the Test Robocall.
From time to time, phone carriers will push an update that disables the "Simultaneous Ring" feature. This causes Nomorobo to disable.
If you notice robocalls are getting through again, please check the Simultaneous Ring feature and make sure it's ON and has the Nomorobo Number listed.
For specific phone carrier setup instructions, please click HERE