Please help me in choosing the right preposition in the below sentence:

The returned values seem a bit confusing on/in its semantics,

Here I'm talking about returned values of a computer programming function, after reading its expected behaviour.

Which one should I use and what is the difference about use in or on?

Please help me in choosing the right preposition in this sentence:

The returned values seem a bit confusing on/in its semantics,

Here I'm talking about returned values of a computer programming function, after reading its expected behaviour.

Which one should I use and what is the difference about using in or on?