Facebook Callback appends '#_=_' to Return URL

Question

Facebook callback has started appending #_=_ hash underscore to the Return URL

Does anyone know why? What is the solution?

Answer 1

For those who are looking for simple answer

if (window.location.hash === "#_=_"){
    history.replaceState 
        ? history.replaceState(null, null, window.location.href.split("#")[0])
        : window.location.hash = "";
}