Web Component not showing Live Data

I enable the web component on my nodes and it works - i can access the web page, and it shows a table with the sensors I have defined.

However, it seems that sometimes it shows the values, sometimes it doesnt. Right now, none of my nodes are showing anything other than the sensor names. Last night there was data in there. I’ve tried restarting them but it makes no difference. I can’t see any pattern as to when they do work, and when they don’t. The log file isn’t updating either.

Anyone know what can cause this?

Posting the sensor part of your yaml may help