Make sure that your phone is running the latest software. You can find out more about the software changes for Lumia phones from here.
- Can I get a notification if I receive call or text messages from blocked numbers?
- How can I remove a number from the blocked list in the call+SMS filter app?
- Can I block phone calls from private numbers using the call+SMS filter app?
- What is the call+SMS filter application on my Lumia device?
- How can I block phone calls and text messages on my Lumia using the call+SMS filter app?