You can no longer move or copy billboards since today's update, they just turn grey.
Thank you, we'll check into this.
This thread was added on November 13, 2019, with posts from iFlak, ZooKeeperZak.
Original Post
In our testing this happens when you switch off the phone tool right after copying the billboard. Try leaving it on the phone tool and see if you still have the issue. We have the bug logged to fix.