It's schizophrenic. I have a shortcut called "What's the spa temperature" that ran fine for years. Of a sudden, now it can't match to it.
"Hey Siri, what's the spa temperature?" => "The temperature outside is 75°"
"Hey Siri, run the shortcut 'What's the spa temperature'" => "I'm sorry, I didn't quite get that!" (x3 repeat, of course, because I can't believe what's happening)
=> rename to: "spa status"
"Hey Siri, spa status" => "...yada yada... it's currently 81 and set to 93, please check back in 15 minutes" (that's the original shortcut that I'd put together).
Suuuuper basic stuff throughout HomeKit, Siri, are horrible. Renaming things doesn't always take, "I'm sorry, I'm having trouble connecting to the internet." Can't properly set an Airplay target by voice.
"Hey Siri, turn off the light!" => (iPhone hears it instead of HomePod) => "Did you mean master bedroom? Kids room? Guest room? Kitchen? Living room? Family room? Office? Dining room?" => cancel, cancel, cancel! :-(