After a successfull post on my site I want to redirect the user and show them a success message. It works if I try to redirect like this:

req.flash("flash", "It's live!");       
return res.status(200).redirect(`/post`); 

But when I try it with variables like this:

req.flash("flash", "It's live!");
return res.status(200).redirect(`../act/${variable}/${variable2}`);

It redirects correctly but doesn't show the "It's live!" message. Why could that be?