Hi FryinDutchman,
It sounds like you may have multiple devices responding to your Siri commands. Here's a resource on How 'Hey Siri' works with multiple devices.
If this isn't the case here's some troubleshooting that should help:
"Make sure your Mac is connected to the internet. Choose Apple menu
> System Settings, then click Network
in the sidebar. (You may need to scroll down.)
Make sure Siri is turned on. Choose Apple menu > System Settings, click Siri & Spotlight
in the sidebar (you may need to scroll down), then turn on Ask Siri on the right.
Note: If you can’t turn on Siri, Screen Time Content & Privacy Restrictions may be preventing you from using it. A family organizer for a Family Sharing group can set up Screen Time for a child and restrict access to Siri & Dictation. See Change App Restrictions settings in Screen Time.
Make sure your Mac has a microphone and that it’s not obstructed by your clothing, body, or other objects.
If you’re using an external microphone, check that it’s connected to your Mac, selected in Sound settings, and that its input volume is set high enough.
Choose Apple menu > System Settings, click Sound
in the sidebar (you may need to scroll down), click Input, then drag the “Input volume” slider.
If you’re using a Mac that supports “Hey Siri,” make sure the lid on your laptop is open. (You can also use “Hey Siri” when your supported Mac is locked or in sleep.)"
You can take a look at the full resource here: If Siri on Mac doesn’t work as expected - Apple Support
If things persist you can reach out for additional support here: Get Support
Take care.