Tag history of discrete value catches values in between

Hello.

I have to store historically values of discrete tag. Discrete, so I do not need any interpolation. So, I have configured a tag like below:

image

I cannot see Value Mode property here, in Ignition 8.1, so I assume Deadband style is the one which replaced it.
With this configuration, the history registered, when the value changed from 80 to 0 is:

Why I am getting this 34.16? What I need is only 80 and then 0.

Thank you in advance.
Best regards,
Maciej.