Not hiding plank breaks maximize on second screen (Mint/Cinnamon)

I'm using Linux Mint 17.3 with Cinnamon 2.8.6 and Plank 0.10.9.1488.
I have three screens: my notebook's screen in the center, an external screen on the left in landscape orientation and another external screen on the right in portrait orientation.
The external ones are 1920x1200 px, the center one is 1920x1080 px.

I want to put Plank on the notebook screen (center) on the left border.
Here's a picture that shows my setup:
http://i.imgur.com/aKZCL7S.png

When I disable hiding in the Plank settings, this works just fine on the center screen. The right screen is unaffected (that's correct), but there's a problem on the left screen.
When I try to maximize a window there, it goes to the upper 120px of the screen (green area in the picture) and cannot be resized any more. Manually resizing it to the whole screen still works, but only when the windows is not maximized.
Obviously, also moving the window with Super+Arrows is broken on the left screen.

This is due to the fact, that Plank reserves space when it does not hide. Unfortunately this also affects the screen "behind" it (in my case, the left screen).
Same problem occurs when I move Plank to the right. Then the other screen is affected similarly.

A fix (if possible) would be great. Please limit this "reserving" space to a single screen. Thanks!