When creating a new Makers Quarter as (or after) the Han, the District Placement Wizard almost always wants to replace my Paper Mill (and when placing a new Paper Mill it often wants to replace a Makers Quarter that's adjacent to the Paper Mill).  It looks like it doesn't recognize the industry already being exploited by the existing district, and thinks the replacement district might do better by exploiting it -- that's what the wizard shows -- but even then, the math in the tooltip is wrong.

Han Turn 20 - MQ to replace Paper Mill.ctr