397438 8/Feb 22:10 24.96438632 730.646G 39hr 58m 56s 21.80PHs 0.06% 415.474M 12.40THs
397279 7/Feb 20:48 24.94621895 721.188G 40hr 28m 43s 21.26PHs 0.06% 420.763M 12.40THs
397238 7/Feb 15:52 24.80670238 724.086G 41hr 2m 34s 21.05PHs 0.06% 426.759M 12.41THs
and variable (vardiff "0"):
397818 11/Feb 03:05 25.28178578 731.051G 41hr 10m 46s 21.18PHs 0.06% 414.693M 12.01THs
397747 10/Feb 16:59 25.21331413 727.871G 41hr 17m 54s 21.03PHs 0.06% 415.750M 12.01THs
397723 10/Feb 13:25 24.93550825 721.073G 40hr 49m 32s 21.07PHs 0.06% 411.102M 12.01THs
but what better, fixed diff or vardiff?
They are related directly, only, to how much of the elapsed time of the 5Nd you mined, which may not have been the full time depending upon various circumstances with your miner and the pool.
Edit: or you could just look at the pool graph and see a spike down that is part of the 2nd 3 and not part of the first 3
See here:
https://bitcointalksearch.org/topic/m.13831674
Lastly you will also note that your % is the same for each of the 6 - try checking that to a few extra places.
That would give the same explanation also.
Left select - fixed diff, right select - 0(vardiff)