as someone who travels all over the world and uses lot of shitty keyboards this sounds a lot of like a localization issue "Control Panel -> Region and Language" ... left alt + shift is that keystoke by default. make sure format (english), location (us), keyboard () and language (english-us,us) is right (my settings). in the last tab is has a 'copy settings' button that will show you all the settings on one page.

the arabic keyboard has a pipe for a left shift key.

if you have the flag app on your toolbar this is also where you rid yourself of it.