I'm looking for a solution to an issue with the print widget in WAB. I found that layers I bring in(service layers) that have grouped label items created by using unique value categories for symbology in arcmap will show duplicate labels within the WAB print legend. There fore if I grouped values 1,2,3,4,5 in a group with label "First5", in my print output file I see the label "First5" 5 different times,rather than once. Image below shows what I get returned.This happens whether I use the ESRI basic print service or my own created print services. It also happens across versions of WAB I just tried using 2.9. It should also be noted I took a look at the webmap(json) submitted to the print task and it doesn't have duplicate legend entries for any layer. Has anybody else had this issue? Has anybody found a solution? Is this a known bug?
If the webmap(json) submitted to the print task and it doesn't have duplicate legend entries for any layer then it is an ArcGIS Server PrintTask issue and not a WAB issue. You will need to report this to esri tech support.