Part stuck too hard to bed + pillowing but fans working

Happens on a part with a large solid flat surface area on the bottom and a large flat place on the top. 

Does this indicate a fan that is under-performing (they both work with fan test) or could it be something else?

Could be also PCB / Heater / Ribbon or underperforming ext FAN(s).

Gather few photos and give us a shout through

Hi Marcin, cheers.

What exactly do you need photos of?

I just bought the printer second hand, it had very recently been serviced by Zortrax so it's a bummer it still has problems. 

Try printing [url=]THAT[/url], make few photos in case of any problems and attach it to Form given above