Does anyone have an actual technical theory of how it’s possible for commands that used to work , say a month ago, to just stop working?

What is it about Siri’s architecture that causes “Set bedroom light to 30%”, a command that worked for years, to randomly stops working on a random Tuesday with no OS update or home change?

I mean, what on earth are they doing on the back end…?

For me, the standout was a period of 6 months or so when Siri stopped understanding the world "half" (as in "lights to half"), and thne it abruptly started working again.