Found you can fix this on 1709 by adding a Registry entry:
REGEDIT
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Input\Settings
New DWORD (32-Bit): EnableExpressiveInputShellHotkey
Value: 1
Then reboot. It's also fixed in the insider build.
That worked like a charm, didn't even needed to reboot, the panel opened directly (on command of course) after closing the Regedit :)
Thanks!