Async/Await Mongoose doesn't always run correctly
I don't know the specifics on that library or method, but I can tell you why it's not working.
"await" will pause only when the right hand side of the statement returns a "Promise" object. In your code example, it seems that the function takes a callback. Callbacks, though asynchronous, are not promises. Perhaps you can check that library's API docs to see if it can return a Promise instead of taking the callback?
You are mixing callbacks with async-await. Don't do that. Please study how they work: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function
Your route handler should be:
exports.GetAllUrls = async function(req, res, next){ try { const urlsArray = await Url.find({uid: req.params.uid}).exec() return res.status(200).json({reply: urlsArray}); } catch(err) { console.log(err); }}.find()returns aQueryobject: http://mongoosejs.com/docs/api.html#find_find.exec()returns aPromise: http://mongoosejs.com/docs/api.html#query_Query-exec