Updating to 8.x-1.2 causes ckEditor issue with drop down lists

Hello.

After having updated from 8.x-1.1 to 8.x-1.2, I'm having some strange issues with some drop-down elements present in the ckEditor: the drop-down list is displayed further away from the initial button (see screen capture for more clarity). Doing a reverse of the update fixes the issue.

Any info would be greatly appreciated.

Thanks,
Bogdan