Alexa responds from multiple devices

I have an OH3 setup with an Alexa echo in each room. I am having an issue with the lastVoiceCommand value being updated on all echo devices that hear the command - often this is 3 or 4 devices, and they all then run the rule triggered by the lastVoiceCommand trigger (and then talk over each other).
I have tried disallowing the rule to run if it is within 10 seconds of the last time the rule ran - this does not work because often the first device to update the lastVoiceCommand value is NOT the device closest to me (so it does stop multiple devices from running the rule - but which one runs it is a lottery).

This is NOT an issue with normal Alexa commands dealt with directly (eg “Alexa, what is the time”) - the closest echo always responds.

I am open to any suggestions. Many thanks.