Problem with automation

Guys who could have this:
To several tracks I registered volume automation, and here the faders do not quite correctly “obey” the registered points. For example, the piano plays at the point machine. -5 dB, but the fader is at an arbitrary (in this case -6.2 dB) volume. Some tracks play in such an incomprehensible form, and even within one track, the same piano plays -6.2 in the first chorus and -5.4 in the second, although again the value of -5 dB is written on all the choruses.
How can I solve the problem?