Yeah, it's been a circus since 16.0 updates. Where to begin?
Generally, a lot of the times Siri doesn't get it right. Doesn't complete the scene, although she says "All Set" and "no it's not all set dear, parts of the house are still dark honey!" Or activates the wrong scene even if she heard me correctly (sometimes on the iPhone I can read she heard me correctly and still activated another scene!) .. A lot of the times Siri answers me on more than one device, sometimes my iPhone, sometimes the iPad, and a lot of times on different HomePods at the same time.. Really even I only have one in the office, sometimes the one in the bedroom (which is accross the hall) is triggered as well as the one in the office.. What? I can't even hear what she's saying back. They both perform, lets say changing the light, they both keep working, and they both do the same thing! Never happened on earlier versions for me. Also sometimes I get the "Aha" or "Ummhmm" thing after she's got my message and already starting doing what I asked her to do. Also several times I had to repeat my command a few times before she's convinced it's something that she should do, she simply lights up, hears it all, and turns off like she's never heard anything, no comment, no replies, nothing. And it becomes a power-struggle, I keep repeating myself and she shuts down on me, and I repeat all over again with a tone of "You'll do this, whether you like it or not!" :-D
So, I'm waiting for the new updates. And until these arrive, I'm currently mainly preferring to use the Home app on whichever device I'm on. Manual tapping works much better for the time being.