If you see this, check out this quick setting that resolved the issue for me in my Warp for Windows installation. 

Once you have changed the setting, you should be able to see the PowerShell launches without issue:

Just as a note as well. I have seen this happen after disabling the SSH wrapper as well, but not nearly as often. If it happens in one PowerShell window, you can open another window at the top of Warp and it will generally open as expected. This is probably a bug in the early release of the terminal. We will see if this gets fixed along the way.