infowindow not allays close

[IJohnGalt]

Hi! first of all cheers to T. Williamson, this code is amazing!

I've found a bug easily to replicate, involving info windows not closing. When you click a marker an infowindow opens, when you click another it closes. But when you apply a filter and then you reload or select a marker again the first one sometimes doesn't close (it seems it happens when the second was affected by the filter.

To replicate it: zoom on the 3 markers in the Atlantic ocean, filter by Michigan tech University, unfilter again or reload. Now click the marker that was not affected and then click anyone of the other two.

I'll try to find a solution (and post it here), although my knowledge of javascript is near to 0, and I'll appreciate if someone can give me a hint or a solution of how to fix this issue.