Hi Abdullah,
You might find this article helpful as well:
Why am I experiencing issues downloading large files from Dropbox?
When you download large files, folders, or collections of multiple items from your Dropbox account, you may receive a warning that the download will take a long time, based on your current internet speed.
In these instances, it can be better to download fewer items at a time, to reduce the strain on your network and avoid needing to restart the process if your connection is interrupted.
Alternatively, you can change the settings in the desktop app to allow Dropbox to use more bandwidth when syncing files :
https://help.dropbox.com/sync/download-entire-foldersCheers!