How to change voice of Mycroft?

I cannot seem to figure out how to exactly to change the voice from mycroft advanced setting.
There are a bunch of text to speech options, like FATTS, ESpeak, Google etc and when I type in one of these in the field, it disappears and the field is empty again when i reopen the advanced setting?
I try to write configuration update in mycroft but it also says no changes applied.

How exactly do I change the voice?