Hi there, Mnbv1. This is a good feature to have on your device will all of the spam calls that comes through. The good news is that this Sounds like the filter just needs to be adjusted. You can follow these steps to add your landline number: https://www.verizon.com/support/knowledge-base-213078/
Please let us know if you have any questions after completing these steps and testing it out. As the cell phone is the only option with Call Filter. If you have any issues with your landline, blocking calls, then you would need to reach out to your landline call carrier.