Xtar vc4s grading accuracy

Hi all, I’m new to this forum.
I’ve got a Xtar VC4S charger and a bunch of Ikea Ladda AA 2450 (white).
I was grading them with the charger and something very strange came up. In every package (4 AA Laddas) there is always one battery that is well below specs. For example, 3 out fo 4 batteries rated 2400 or above, the fourth 1200 or 1600.
I’m beginning to questioning maybe the Xtar accuracy.
Is there anyone that had the opportunity to test this hypothesis?
Some weird results here. I’ve cycled some Laddas 2450 (white) in the Xtar Vc4S, grading mode, and here’s the result:
Ladda 1 1151 - 2316 (181mohm)
Ladda 2 1265 - 2404 - 1278 (31mohm)
Ladda 3 2056 - 1201 (32mohm)
Ladda 4 2034 - 2424 (124mohm)
Cycling method: a grading cycle consists in charging - discharging and measuring the capacity, and charging again.
Then rest for an hour.
The the cycle starts again.
What puzzles me the most is: how erratic those capacities are and couldn’t find neither a correlation with internal resistance
What’s going on here?

I don’t understand what you mean by cycling. Did you keep each battery in the same charging bay. It is quite well possible that the four charging bays don’t have identical properties. Try and swap the batteries to another charging bay and look what happens.