slug is only changed if title changes and it has not been set before.

fet2020/posts/static/js/auto_slug.js

@@ -1,5 +1,7 @@
 window.addEventListener("load", function() {
     (function($) {
+        var slug = $("input#id_slug").val();
+
     	$("input#id_title").on('input', function() {
 	    var title = $("input#id_title").val();
 	
@@ -10,7 +12,7 @@ window.addEventListener("load", function() {
 	    getUrl = window.location
             baseUrl = getUrl.protocol + "//" + getUrl.host + "/" + getUrl.pathname.split('/')[0];
 
-	    $.ajax({type:'GET', url: baseUrl + 'posts/func/slug_calc', data:{'title': title }, complete:complete});
+	    $.ajax({type:'GET', url: baseUrl + 'posts/func/slug_calc', data:{'title': title, 'slug': slug }, complete:complete});
         });
     })(django.jQuery);
 });

fet2020/posts/views.py

@@ -146,7 +146,9 @@ def slug_calc(request):
     if request.method == "GET":
         get = request.GET.copy()
         title = get["title"]
+        slug_str = get["slug"]
 
+        if not slug_str:
             datetime_now = timezone.now()
             date_str = datetime_now.strftime("%Y-%m-%d")