I was already on v3,3
However, having played around with the addons, the offender seems to be the
addon "DuckDuckGo Privacy Essentials".
If the Privacy Essentials is enabled when DWC initiates, the the tool temperature graph and the Height map do not work (tool graph is blank, height map is not available. However, proving PE is disabled at the start, then enabling it during the session doesn't seem to affect DWC, the graph and height map stay available.
But if I then close the tab but not the browser while PE is enabled, and then re- connect to DWC n the tool graphs and height map are once again disabled. The first time I checked for Add-On effects I did not close and reconnect for each add on disabled.
(DuckDuckGo is my chosen search engine and the Privacy Essentials claims to enforce "no tracking" protocols and other good practices, although I still seem to end up with an absurd number of tracking cookies despite its actions)
So a sort of solution at my end, thank you.