You probably need to raise the default upper center frequency.
In the Measure screen, got to the Acquisition tab (F5) and then the RTO tab (F10).
Increase the Upper center frequency from 5000 Hz to whatever you need (for example 16000Hz).
Let me know if that works for you,
In addition to Jacklyn's suggestion, also go to either Acquisition Setup or Measure, F5 Acquisitionb and increase the fixed sampling Bandwidth. The two fields are linked and the RTO Upper Frequency cannot go above the Fixed Sampling bandwidth. The main reason is that the throughput data will have that bandwidth and we cannot calculate octave bands above it.