Frequency
is the desired frequency of the PWM signal. On devices with 2
channels, the
Frequency must be the same on both channels. Not all frequencies
are available at all oscillator settings. For the non-long versions of PBP (PBP and
PBPW), the highest frequency at any oscillator speed is 32767Hz. The lowest
usable HPWM
Frequency at each oscillator setting is shown in the following table.
quote from the pbp3 manual

did you actually check the resulting freq, it can be done manually of course

would a pull down resistor (say 1k) make the trace look better