in kq6, on the crown castle entrance screen with the two guards, try following the path to the left.

I think KQ6 is very sensitive to where you click, you usually need to click really close to the screen edge. If there is a touchpad style input mode (where moving your finger over the screen just moves the cursor in that direction) you should try that and move the cursor really on the edge. its not...

One thing I noticed in Space Quest 4 that I can't actually go east or west (the screen to the right or left) in the game - if you try to walk off the screen, it just doesn't trigger. Im having the same issue with not being able to exit screens on the left or right side. I have noticed it with sq4, ...