2 EU17 (Glock 17) gas powered

So here we have 2 EU17's with a small flaw. The black one works and cycles as it should no problem whatsoever. The blue one fires but locks the slider into the open position after every shot. I'm not entirely sure why and I don't have the energy to figure it out. Comes with 2 mags (NOT GAS TIGHT) so will need replacing or servicing. Hard case and some spare parts including new grip for the blue one. Buyer to pay for postage if needed. See you out there ☺️