Repeating Group Constraints - Any field contains now showing phone/zip number?

Could you help me about why the ‘Any field contains’ constraint in a repeating group works for fields storing strings, but doesn’t work for fields with a data field type which is text that store numbers? For example, I can search for any word in my table, but when searching for fields like phone numbers or zip codes (these are storing text), the constraint doesn’t work. Could anyone please help identify the reason for this behavior?