Siri on HomePod controls wrong lights

Your lights need to be assigned to rooms and match with the same room names in home-kit, you’re not looking to assign lights to rooms the HomePod is in.

You dont say which lights you have. You need to research that brand, see if it has an app to guide you through set up.

I have Philips hue lights and the supplementary hue App to set up my lights from the start. I set each bulb to the room it was in . The bridge was the only accessory I set up in home app. The bridge is what’s storing all my settings. Every time I buy a new bulb, it needs a software update and the home app can’t tell me this, the hue app does and performs the update.

Once i had set up all my hue lights in the hue app, they all showed up in home app with correct rooms, I did mess up a few room names and the hue app told me I had a Homekit mismatch and to correct it. The hue app did this for me .

My homepods are flawless with the lights. I can tell my bedroom HomePod to turn on or off the living room lights and my livingroom HomePod can do bedroom lights and vice versa.

I can also use my Apple Watch, iPad or iPhone to give commands. HomePod is just a hub, Siri is just taking commends,

Somewhere you have a mismatch going on. If you’re using a bridge, it would need to be reset also. Since it stores all the settings,

I've not tried other bulbs, I’m sticking with hue since I love how smooth the set up is.

Well I think now, you do have to specify which lights. I just asked Siri on my iPhone to “turn off the lights” and it did all my lights in every room. Except as I said, my HomePods still do it without specifying which room

You can however create Siri shortcuts but I’m no good at advising on shortcuts, you’d have to look that up. Or you can create scenes with the lights in the home app. I tried goodnight and good morning for scenes. Sure it worked but put my lights on a very dim level on the good morning scenes, so I didn’t like that. To specify which scene or shortcut goes to which lights, I suppose the phrasing would have to differ, like turn on the lights vs turn the lights on. Of course that can get confusing on what you’re supposed to say.but you can pick which lights it does though.

as well as using Siri shortcuts, there’s a shortcuts app, but I don’t know if it does home-kit, ios13 promises to improve on the Apple shortcuts app though, I can’t figure out how to use the shortcuts app. You need to look on YouTube at tutorials.

Here’s the app in case you want to take a look at it:

Shortcuts by Apple

https://apps.apple.com/ca/app/shortcuts/id915249334

I’ve gotten a bit lost on what you say isn’t working. 

You say you have some smart wall switches? Is one in the dining room? If so, could it be that it’s the switch that’s gotten muddled up and this is why any bulb works? Could also be why it’s not understanding the correct rooms and always doing the dining room? The switches might have the mismatch. 

Sometimes Siri gives no feedback, just does it. 

As for you wanting to tell the homepod to ”turn on the lights” and this happens with the lights in the same room HomePod is in, yes mine can do that and you’re saying HomePod used to do this but now it doesn’t? Did I see you post about a power outage messing up the homepods? It might help for you to reset the homepods

Make sure all your rooms are spelled exactly the same. I.E: Livingroom vs Living Room. Or simply just try renaming the rooms to see if that helps, making sure they still match with the corresponding lights and switches.