Title says it all.
Since upgrading from 17.10 to 18.04 Alt+Tab works fine i.e. switches apps cycling forward. But Alt+Shift+Tab does not switch apps backwards.
I went to Settings > Shortcuts and noticed that the shortcut for Switch applications is Super+Tab.
I tried Super+Tab and Super+Shift+Tab and they worked as expected, but i'm hardwired to use Alt+[Shift]+Tab. So I switched this shortcut to Alt+Tab.
Still Alt+Shift+Tab only switches forward, and not backwards.
Changing the shortcut to Super+Tab again works as expected for both forward and backward switching.
Any idea how to make the Alt+Shift+Tab work for backward app switching?