My raw log has hundreds of these warnings which makes it difficult to find actual messages. My guess is this is something to do with zigbee and mqtt, but how do I track this down?
2026-01-17 10:12:05.384 WARNING (MainThread) [homeassistant.helpers.template] Template variable warning: 'dict object' has no attribute 'displaymetric' when rendering '{{ value_json.displaymetric }}'
Look thru your templates for something with that word in it. That’s a variable that the template cannot find.
Where would I find all the templates? I’ve checked automations.yaml and it doesn’t appear in there. I also checked the 3 helpers I have of type template and they don’t contain it either.
This is likely not a template you have generated but actually a parameter in an mqtt discovery message for your device(s).
Which device(s)?
Not possible to say from that error log unfortunately.
You could use MQTT Explorer to trawl your broker for discovery messages in the homeassistant topic to try and identify them.