Steps to Reproduce:
- open the integrated terminal and have it output some text so that scrolling happens
- scroll up a little and select some text (see screenshot1)
- press ctrl+c
- press ctrl+v
Screenshot1:

What happens: terminal scrolls to the bottom and the text that was previously in the clipboard (here that's not what I copied) is pasted, instead of the one I just copied using ctrl+c
Now, if I don't end the selection (ie: release the left mouse button) before reaching the left side of the screen, it will work:

I am using the latest insider build (211ffdf) on Windows 10 (64bit).
I tried and could not reproduce the problem on a standard cmd prompt.