Hi,
out of necessity I had to load the arcgis js sdk locally,
and I noticed a problem that I didn't have before and that I couldn't solve,
in a nutshell I have 3 featurelayers on the same zoom level,
one is a shapefile so let us not consider it, and the other two are derived from a geojson with points .
Both featurelayers have a refresh rate of about 10 seconds,
depending on how these two are loaded the last one has a strange glitch at refresh which the other one does not.
A black rectangle appears on the icon for a fraction of a second, which is very annoying.