speed variation in share it app slow transfer how to make it fast

I use share it app. The version on my Windows 10 desktop of Share it app is latest and updated screenshot below


Now when I try to transfer from my android phone any thing to desktop using share it app there is speed variation I have captured screenshots these will make situation clear

Attachment 260634
You can see in above screenshots speed for same transfer is varying from 0 Kbps to 2 Mbps.
Occasionaly large transfers broke also as in screenshot above 9 Gb telegram files could not be transferred.

So I want to understand what is the problem.Which log file I can check to understand the problems and how can these be fixed? Is there a better solution for me?