LD highlighting not working?

[Matthew Maher]

I'm just using pheweb for the first time (nice tool!) and everything's pretty much gone great, except that I'm not getting the LD-highlighting feature when zooming in to a region view.   My variants do appear to be recognized against the build (I'm using hg38) as the RS#s are getting shown.  But no LD highlights. 

Can anyone recommend how to diagnose what I'm doing wrong?  I didn't see any discussion of LD-highlights in the README (but maybe I missed it).

Thanks for any assistance