also the smaller air hole vent on the side open
That's your problem - the secondary air vent needs to be closed.
The main air vent for anthracite is on the back towards the lower left. You'll need to remove the shaker grates to access it; it removes with a screw or two.
Also, there are three sliding metal sliding plates on the bottom of the stove. They are cleanout covers, You'll want clean behind them as flyash can really accumulate in there. And finally reach into the thermostat flap entrance to remove any old coal or debris that may have accumulated in there. Once a month or so I stick the vacuum hose in there.