According to the api documantation you should use LotSizeFilter for limit order types and you should use MarketLotSizeFilter for market order types.
As you will see below screen shot, MarketLotSizeFilter.MinQuantity ==0 and MarketLotSizeFilter.StepSize ==0 meaning that there is no constraint on stepsize and minquantity. But when you want to place a market order with MarketLotSizeFilter applied it does NOT success, it fails of stepsize and/or minquantity.
A market order is succesfully placing when i applied LotSizeFilter, not MarketLotSizeFilter !!!. So i always use LotSizeFilter for market orders.
Can you verify to apply LotSizeFilter for market orders? If so why and where do we use MarketLotSizeFilter?