I have my PC set up so that the right mouse button is the primary one, et vice versa. Minecraft Windows 10 Edition does not appear to recognise this correctly when using the mouse to control the game; even though items and blocks can still be used/placed using the left mouse button instead of the right mouse button, and controlling inventories still functions as expected (left-click to split a stack instead of right-click, etc.), the left mouse button still attacks/destroys instead of the right mouse button.
Thank you in advance for taking care of this highly irritating issue.
UPDATE: I have just discovered that this bug makes it impossible to destroy a block which has a use function (workbench, furnace etc.) because every time you go to destroy it it opens the GUI for that block. >_<