What is the reason of undesired peak current in PFC non-isolated boost converter?
I observed same behaviour in interleaved PFC controlled by MCU. At higher load same peaks at coils currents affect the line current. Higher Proportional value of current loop controller help slightly together with some feedforward shape which help current controllers performance. Some people have similar problem with TI pfc IC, but there was the problem with some clamping of internal structure - the solution was to decrease shunt value. 



(Image source: TI E2E forum topic: UCC28180: UCC28180 PFC : distorsion of the PFC coil current [sic])

But in my case the shunt voltage after amplification with OPAMP is far from ADC max 3.3V. My current scale is 8Amps and issue is at 3-4Amp