Hi there,
So , even the wire length’s has to be the same, I suspect the OP was off a tad (13.56MHz) for the smaller one and that was why he thought using a larger antenna(then HAD to use the CAPs) to get it working. HAd he tuned the small one with some caps it would have worked better IMO.
YMMV. 
For a 1.4 µH antenna, the required total capacitance to resonate at 13.56 MHz is:
- Total capacitance: 98.4 pF
- Each capacitor: 49.2 pF (one from NFC1 to GND, one from NFC2 to GND)
Recommended Capacitor Values
- Use ~49 pF capacitors (C0G/NP0 type) for stability.
- Ensure your PCB layout doesn’t introduce excessive stray capacitance.
try that and be sure your using the correct side as well, the adhesive side is aluminum and doesn’t pick up well or at all from the BACK!
HTH
GL 
PJ 
When it’s working I get a good 3 inch operation on the dev kit
You don’t have to use SMD caps either , Seeed should offer:
A) a standard antenna PAD with caps on it, one could just solder on.
B) a Larger NFC selection of hardware.
C) give me free stuff forever 
Ok maybe not the last one.
I see an opportunity for a small pcb with everything on it for long and Short range.