the fastest test can be performed by yourself:
Assuming you have a linux based system, type:
cat /var/log/openhab/events.log | grep Est
This should show you what these items (and all other Items having “Est” in their name) have been set to by the weather binding. You might need to change the path to the location of the logs in your system.
On windows, I’d suggest you open the events.log in an Editor and do a search for “Est”.
This will clarify if the Items do get set at all. From there, you can start pinpointing the problem.
I use Weatherunderground and though I first understood it just would not provide info on the UVI field, apparently it does. But indeed it may depend on the station you are connected to My field is updating perfectly and is in line with what I get from a weather widget on my phone