On the PTR the Micro Menu doesn't work and instantly causes an error.

Interestingly the micro menu isn't centered when in a vehicle. This occurs with the default UI, no addons enabled.

And in the pet battle UI

Think I've got this sorted now. Other than the above positioning issue that I thinks a Blizzard issue.

Leaving this open whilst I'm still testing.

Tested this with a completely clean addon folder and fresh WTF folder on PTR. The above issue persists, Blizzard issue. Going to assume they'll fix it. Closing this then since nothing more I can do to the micro menu.