Sitecore Media Item getting downloaded on click of media item

Question

Media item are getting stored on azure, for this I have overridden Media library classes. Now what happen when I am selecting any media in Media Library to see,

It gets automatically downloaded. It is happening for every media type item like pdf,zip, exe, xls except images.

For code : Overridden Class: Sitecore.Resources.Media.MediaRequestHandler

protected override bool DoProcessRequest(HttpContext context)
            {
                Assert.ArgumentNotNull((object)context, "context");
                MediaRequest request = MediaManager.ParseMediaRequest(context.Request);
                if (request == null)
                    return false;
                Sitecore.Resources.Media.Media media = null;
               // var mediaPath = request?.MediaUri?.MediaPath.Substring(24);
                string mediaPath = string.Empty;
                bool mediaById = false;
                if (request?.MediaUri != null && !string.IsNullOrEmpty(request?.MediaUri?.MediaPath.Substring(24)))
                {
                    try
                    {
                        var mediaGuid = Guid.Parse(request?.MediaUri?.MediaPath.Substring(24).Replace(" ", "-"));
                        mediaPath = request?.MediaUri?.MediaPath.Substring(24).Replace(" ", "-");
                        mediaById = true;
                    }
                    catch (Exception)
                    {
                        //log nothing
                        mediaById = false;
                    }
                }
                if (!mediaById)
                {
                    media = MediaManager.GetMedia(request.MediaUri);
                }
                else
                {
                    var mediaItem1 = Sitecore.Context.Database.GetItem(mediaPath);
                    if (mediaItem1 != null)
                    {
                        Sitecore.Data.Items.MediaItem mediaItem = new Sitecore.Data.Items.MediaItem(mediaItem1);
                        if (mediaItem != null)
                            media = MediaManager.GetMedia(mediaItem);
                    }
                }
    
                if (!IsCdnMedia(media))
                    return base.DoProcessRequest(context);
    
    if (request.Options.Thumbnail && (media.MimeType != "image/jpeg" && media.MimeType != "image/png"))
                {
                    //request.Options.UseMediaCache = false;
                    return base.DoProcessRequest(context, request, media);
                     
                }
    
                return this.DoProcessRequest(context, request, media);
            }
    
           
           
            private bool IsCdnMedia(Sitecore.Resources.Media.Media media)
            {
                return (media != null && media.MediaData.MediaItem.FileBased);
            }
    
    
            
            protected override bool DoProcessRequest(HttpContext context, MediaRequest request, Sitecore.Resources.Media.Media media)
            {
                Assert.ArgumentNotNull((object)context, nameof(context));
                Assert.ArgumentNotNull((object)request, nameof(request));
                Assert.ArgumentNotNull((object)media, nameof(media));
                if (this.Modified(context, media, request.Options) == Sitecore.Tristate.False)
                {
                    this.RaiseEvent("media:request", request);
                    this.SendMediaHeaders(media, context);
                    context.Response.StatusCode = 304;
                    return true;
                }
                this.ProcessImageDimensions(request, media);
                MediaStream mediaStream = null;
                if (!IsCdnMedia(media))
                {
                    mediaStream = this.GetMediaStream(media, request);
                }
                else
                {
                    CloudStorageProvider cloudStorageProvider = new CloudStorageProvider();
                    var stream = cloudStorageProvider.GetStream(media.MediaData.MediaItem);
                    mediaStream = new MediaStream(stream, media.MediaData.MediaItem.Extension, media.MediaData.MediaItem);
                }
                if (mediaStream == null)
                    return false;
                this.RaiseEvent("media:request", request);
                if (Settings.Media.EnableRangeRetrievalRequest && Settings.Media.CachingEnabled)
                {
                    using (mediaStream)
                    {
                        this.SendMediaHeaders(media, context);
                        new RangeRetrievalResponse(RangeRetrievalRequest.BuildRequest(context, media), mediaStream).ExecuteRequest(context);
                        return true;
                    }
                }
                else
                {
                    this.SendMediaHeaders(media, context);
                    this.SendStreamHeaders(mediaStream, context);
                    using (mediaStream)
                    {
                        context.Response.AddHeader("Content-Length", mediaStream.Stream.Length.ToString());
                        WebUtil.TransmitStream(mediaStream.Stream, context.Response, Settings.Media.StreamBufferSize);
                    }
                    return true;
                }
            }

Does anyone faced such issue? or any suggestion.

Note: Sitecore is upgraded from 8.1 to 9.2.