I am fairly sure it is because of something related to what the button considers. There are 2 reasons I am considering:
- It looks like the button doesn't IMMEDIATELY cancel speech, it lets the token finish or something. The continuous
///are considered all part of one thing so won't cancel until the next space. - The
///are considered as already spoken or something, scheduling cancel for the next space.
To summarize, the button considers long strings of /// to be part of one large thing, and the cancel will happen at the next space instead of immediately.

