Having the same issue. Seems like some of the windows are clickable only sometimes. And hovering over items/buttons in inventory is blinking. I can provide video if needed. Please look at this issue, game is great but almost unplayable at this state. It looks like bottom conversation window works fine. But inventory window and combat log window are definitely bugged.

Steam - Divinity: Original Sin EE v2.0.119.430

My specs:
macOS Sierra 10.12.6
MacBook Pro (15-inch, 2016)
2,6 GHz Intel Core i7
16 GB 2133 MHz LPDDR3
Radeon Pro 450 2048 MB