Boost Converter Question

I have a boost converter circuit attempting to boost a 1.8V signal up to ~6V. Right now the duty cycle is about 70%. There is a control logic circuit consisting of a comaprator, VDAC, and PWM which reads the output voltage of the Boost Converter and modulates the duty cycle based on the result. The reading is taken from the output through a voltage divider to bring it down to the MCU’s voltage levels.

Now for the question part. When I start up the boost converter and allow it to reach steady state, it goes up to just under 6V. This makes sense and is exactly what I want. But when I connect a load in parallel with the divider circuit, the voltage drops. Does anyone know why this is happening?