It was a function in the init.js file (inst/tablerDash-0.1.0/init.js). I forked to my own repo and commented out window.history.replaceState.
if (typeof workerId != "undefined") {
var pathname = window.location.pathname;
var newpath = pathname + workerId;
console.log(newpath);
window.history.replaceState( {} , 'newpath', newpath);