Seven ult bug with keybinding

[maki]

I remap space to fly up on seven ult. When I bind any new key to cancel the seven ult, it does not work.
Pressing space after seven ult starts will cancel the seven ult, if I push space before the fly up and fly down text appears. Even when space is not bound to cancel seven ult.

 

[Walmart Shoes]

This was happening to me and was very annoying.

What seemed to work for me so far is to rebind (or unbind, in my case) the "cancel ability" button bind in general settings and not hero-specific. It seems like since I still has space mapped as the general "cancel ability" button, it was taking precedent for the startup (first second or so) of the ult.