Not capturing some features on a webpage

[GeraldCNelson]

The page at this link includes ovals to indicate air quality
webshot("https://www.purpleair.com/map?&zoom=12&lat=39.09864026298141&lng=-108.56749455168722&clustersize=27&orderby=L&latr=0.22700642752714373&lngr=0.4785919189453125", "paMap.png")

The png it produces doesn't include these ovals.

I'm using webshot version 0.5 with the package process at version 2.0.01 (the newer source version, 3.0.3, won't compile on my mac. I use home-brew and the installation doesn't pickup the location of clang.