BQ40Z50-R2: Full Capacity differs from nominal

Hi

some months ago I started experimenting with BQ40Z50. After doing the charge-discharge cycle as suggested, I founf that Full Capacity of my  battery was quite close to the nominal value (2600 mAh)

and ASOC was, let's say, 99% while RSOC=100%. That's OK

Now after using my batteries for a while, I discovered that Full Capacity has fallen to 2360mAh and while RSOC is 100% the ASOC is only 91. What can be happened? For what I know, I only  changed  my load:

my first tests was with a discharge current of 1A while now I'm trying with about 3A ' cause this will be my real situation.

Thanks