I see you have the Toolbar is floating mode can you please try to dock with the window then check.
Also, you wrote you have dual monitor setup, what happens when you remove the second monitor.
the problem stays the same (with docked or floating toolbar).
if I maximize indesign to my 2 monitors...the palette appears on the second monitor.
if i 'scale' the indesign window to monitor 1 it appears in the middle of the first monitor.
if I disable the second monitor, it appears at the correct place.
also tried Photoshop CC, but it's not a problem there.
This is a strange behaviour, I don't know if other user are also having this issue.
Could you update your computer's display drivers ?
updated my display drivers. problem still remains.
It seems indesign cc is the only program with this behaviour.
I also tried illustrator cc and everything works fine there.
In indesign the menus seem to appear in the exact center of the monitor.
I will try and test the issue.
Will keep you posted.