5D3 - AF Microadjustment bug?

Hi!

I have found an interesting problem with my 5DMkIII.

I have set up AF Microadjustment (AF MA) value for one of my lenses. Usually i can find this information in EXIF (in Canon DPP you can see the value of AF MA). The problem is, that in series of (for example) 20 pictures i can see the value of AF MA which was used only in 10 pictures. The rest of pictures is without this information and it looks like that the AF microadjustment wasn't applied (the focus isn't so precise).
I can't understand, why is AF MA applied sometimes and sometimes not.
Has anybody the same experience?