So these XBP9B-DPST-021 modules are supposed to transmit 24dBm(0.25w) on power level 4 but when I do a range test between 2 modules (1m apart on the bench with 3dB antennas) using the XCTU software it reports -40dbm. Even with a 22dB fade margin (http://www.digi.com/technology/rf-articles/frequency-comparison) that corresponds to a transmit power of only 8dbm?
How are you measuring this? Are you connecting a Spectrum analyzer to the radio and measuring the output power?