Raising the Pitch Shortens the Segment at the Same Time

I tried to raise the pitch of a note of the vocal by using the change pitch effect. I increased the pitch by 5% and obtained a satisfactory result. However, the segment thus edited is shortened, so that the rest of the song is no longer in alignment with the other tracks, and I have to use the tempo effect to slow down the segment a bit. This is unexpected because the pitch effect screen claims that the tempo would not be changed. Why does this happen?

As it says in the manual, Change Pitch does not keep the length exactly as before.

For more accurate length, use the more advanced “Sliding Time Scale/Pitch Shift” effect: http://manual.audacityteam.org/o/man/sliding_time_scale_pitch_shift.html