L2A - Different pixel values

When I take L2A products directly from the open hub, I noticed that pixel values in the overlapping areas of adjacent granules differ. Two adjacent granules, the same orbits, and the recording time, in the overlapping areas have different pixel values in all bands.
For example - granules:
S2B_MSIL2A_20181012T094029_N0209_R036_T33TXL_20181012T145646
S2B_MSIL2A_20181012T094029_N0209_R036_T33TXK_20181012T145646

Why is that so?