This article seems to miss the fact ISIS took over Mosul international airport in 2014. Surely they got luggage screening machines in hand by then already.
My guess would be that the gear at Mosul would not be as advanced as elsewhere.
Well, for whatever reason, they stole more equipment more recently. Could be that the new stuff is more advanced, or maybe we bombed the gear they took from Mosul. I don't have more details that would provide insight.
Not sure, because the destinations countries for the planes departing from there have some interest (a bit like the US forcing some theater on Europe), and there is some international help for military and security theater gear.