I have a two monitor setup like this

``` 
+-------++-----------------------+
|       |                        |
+-------+                        |
        | <--                    |
        +------------------------+
```

Left side is a laptop 2K screen, right side is a DP 4K monitor.

On the laptop bottom, i have a 'taskbar' with application launcher, icons only taskmanager, system-tray and on the bottom of the 4K monitor, there is also a panel with icons-only taskmanager (this is not the whole screen witdth, just 1/6th of the width (see 'vvv' below to indicate the current - horizontal position). This panel has autohide activated and is working ok.
```
|
| vvvv
+-----------------------------+ 
```

Now, i tried putting this small panel vertically, just so it's attached to the lower left corner of the 4K monitor (see '<--' in above picture where i want to put it)
This also works ok, but the auto-hide feature does not - the panel is always visible

I know, that's a strange setup, but still very handy, because this lower left area of the 4K monitor is like an 'infinite target area' (Fitt's law) that's very easy to reach with the mouse.

Would be nice if autohide would work here as well