I'm using MINGW64 from the git-bash.
If I type the command 'clear', my cursor jumps to the beginning of the window, but the text doesn't disappear:

I have similar issues using vim in my bash. If I try to delete a char, my cursor moves, but the chars doesn't disappear, too.
In vim I get another error, when moving the cursor with the arrow keys:

By any chance you found solution to it?
The clear error is a duplicate of:
https://github.com/zeit/hyper/issues/1809
The error isn't fixed, yet, but you can temporarily clear the complete window with Ctrl + Shift + K.
For the cursor problem in vim I don't have a solution.
Quick question, sorry that it is unrelated. I am trying to make Hyper use the mingw64 console, how did you make that happen?
in hyper.js file put
// for environment variables
env: {
TERM: "cygwin"
},
^ your solution
Most helpful comment
in hyper.js file put