Hi,
for system volateges from +20 V to +36 v they recommend the connection of the boost capacitor towrads VDD.
The front page of the datasheet states "
The MIC5021 high-side MOSFET driver is designed to operate at frequencies up to 100 kHz (5 kHz PWM for 2% to 100% duty cycle) ... ". With a period of ~32 µs your switchin frequency is about 31.25 kHz, where your on-time is about 4 µs, leading to a duty cucle of ~8 %. So your switching frequency might be too high. Which MOSFET's are you using?
As
@KlausST pointed out, a schematic would be quite helpful.
BR