George,
The fifth string should be tuned to A for this song. Not G, which would clash with the harmony.
If you want, you can try playing it with no capo at all, just standard G tuning gDGBD.
You’ll hear how it’s supposed to sound and then you can add the capo to the 2nd fret and tune the 5th string to A and it should sound the same just up a whole step.
If you’re still having trouble let me know.
– Mike