It would help if you could post a screen shot of the Jan dividend transaction(s). I think if it was a bug then it would do it every month.
Here's the taxable account which has less activity so it's easier to see what's happening:The "Remove shares" transaction was created by Quicken when I did the January dividend reinvestment. I did the "add shares" manually to reverse that. Nothing unusual about the January dividend, Quicken just got weird with it.