A few ideas. 

1. Looks like you are searching on a string field (maybe a formula).  But you are showing the original telephone number field in your table (to get the formatting).    Are you sure the formula is working and that records you expect have the right value in the string field?

2. Are you sure the string field is not a long text field?  Salesforce will not allow querying on long text fields. 

It’s a 10 character text field.

User error. Got it

Glad to hear.  I was scratching my head about this one.