Echo completely unable to use ultimate with controller in use

I play Overwatch using an Xbox controller in the left hand and mouse in the right hand. On all heroes, Y is mapped to ultimate. In the practice range with Echo’s ult ready, I wasn’t able to use the ultimate by pressing Y or by using Q on the keyboard, in both cases it made the error sound used for abilities not yet ready. I switched to Hanzo and had no issues using his ultimate, so this seems to be exclusive to Echo