Okay, first, there's a problem with FE7/FE8 coloring on the beard that I feel should be fixed.
Second, the reason that your mouth is having problems is because the portrait is formatted incorrectly. Download Usenti and open the portrait in it. The first thing you'll see is that the portrait has more than 16 colors, so I'm surprised that FEB would open it at all. Second, turn the grid on
Hit ctrl + G and make the grid 8x16
You should see
Look at the grid in relation to the frames, then compare it to the portrait overall; your mouth frames aren't in the same grid area as the portrait. What you were looking for is
If you still don't understand where you messed up, look at the frame I put in in comparrison to the one right below it.
Hope this Helped
Edit: Rip Spoiler tags