The tip-off for your situation was that the Ohms Doubled. And that is Exactly what happens when you Take Out one Coil in a Dual Coil set-up.
I just Hate Slotted Screws on Atomizers. Kinda just Hate Slotted Screws Period.
BTW - Sometimes there can be a Rough Edge or Burr on the end of a Screw where the Chamfer meet the Screw Flat. And this Rough Edge/Burr can Shear the coil leg when you Tighten it down.
Always good to give them a Quick Check with a Magnifying Glass. And maybe a couple of Light Passes with a Jewelry File or an Emory Board if they do.