Macro no longer works?

Took a year break and now my macro no longer works for the flying mount but still works when using the tiger?

#showtooltip
/cast [mod:shift] Onyx Netherwing Drake; Black War Tiger

The tooltip changes correctly to the drake but hitting the button does nothing

What key is it bound to and are you using the keybind or clicking it with your mouse?

Clicking while holding shift.

Click bindings are an absolute mess right now. Try both right clicking and left clicking to see if that helps.

More info: