For the Gandhari script, in the previous Keyman version, the left Alt key was functional. But in the latest Keyman version, the right AltGr is functional. Is there any setting to revert to the left Alt key.
The problem is that Left Alt is not available on macOS and we wanted the keyboard to be available on Linux, Windows AND macOS.
I would note also that Left Alt is not recommended for use as a modifier for a keyboard layout, because it is reserved by Windows as an access key for menus and dialogs. Overriding it means that users cannot press, for instance, Left Alt+F to access the File menu. For some users who may for example have difficulty using a mouse, this is important functionality to preserve.
There is one complication with Right Alt: a few small laptops and reduced size hardware keyboards do not include a Right Alt key. For those keyboards, you can select an option in Keyman Configuration, “Simulate AltGr with Right Alt” (AltGr is another name for Right Alt).