Change the font to not have ligatures

[richardanaya]

Your font has something weird going on with "fi" sequences. My guess is its because the font you are using has ligatures, usually there's a version of the font without it.

[narimiran]

My guess is its because the font you are using has ligatures

Your guess is correct. But this is something that does not bother me (if it were, I would have chosen some other font).

I'll leave this issue open for now, to see if somebody else has the same opinion/problem as you, but I might close it in the future.