Biden got fewer votes than Hillary Clinton did in 2016 in ALL urban areas of the country EXCEPT FOR Milwaukee, Detroit, Atlanta and Philadelphia.

Simply not true. Take for instance Minnesota’s urban 5th District (Minneapolis and suburbs). Hillary Clinton got 273,402 votes, Biden got 328,766.

…the vote even exceeded the number of registered voters.

Apples, meet oranges. It’s easy for the vote totals to exceed the number of registered voters. Many states have same-day registration so that you can register on Election Day. The number of registered voters is recorded before Election Day.

No magic involved.