Yep, not to belabor the point, but yes, that's the cylinder order I used, and I made sure the wires went to the numbered coil locations.

I did indeed use my feeler gauge (blade type, not wire type) to check the gap on the plugs.

I know the wires are in the correct location. I know the plugs are properly gapped and correctly inserted.

Does anyone have any other suggestions?

Still baffled...