unknown callers not showing number - why?

[boe]

Hello,

When a call comes in it says unknown - if the person isn't in my address book I can understand it not knowing who it is but why isn't their phone number showing up? I could swear it was before. These aren't hidden or private numbers.

I'm not using any contact apps - just vanilla set up.

[draghn]

Are you sure they aren't hidden? Sometimes I get unknown and find out later it was a private number. Other unknowns show the number below the android graphic...