Problem with avy and ace-link

I have an issue with both avy and ace-link. Activating any of these modes will make each line slightly higher. This is problematic because (1) last lines of the buffer will suddenly disappear and (2) every line moves down a bit.

I thought it might be due to the bold face so I tried to remove that but the problem persists.

Is there a way that activating these modes would keep the line height the same? The "tango" theme provided with Emacs doesn't have this problem.