100 kbs on 1 gigabyte,100+ megabit internet speed. Ah yes the best download manager i seen in an while,please decrease download speed.

A single instance of slow speeds means absolutely nothing, especially without any links showing that it is not the server providing the download in the first place.

You should first get a better understanding of how downloading files works.

I have a gigabit connection, and some sites I get well over 100 MB/s, and some I get 2. It's not FDM's fault that some sites simply won't give me the same speeds as other sites.

Your ISP rating isn't the same as DWN/UPD speeds there are many factors their side/site and your side that can make or break connections or slow to a crawl. And without any links to verify what is going on this goes mostly nowhere here.