When using segments, it is common to enter in a value in the keywords and phrases portion without actually saving the keywords.
Here is an example of how it should look after entering the rules:
When entering a new keyword or phrase, clicking enter will submit in the new rule. Oftentimes, it will be entered without actually pressing enter before saving the monitor.
If that is not the case, please email firstname.lastname@example.org with details on the segment and monitor being used.