Searching by Role requires content to search beyond the tag. But it doesn't seem to be working. the NYPL collection has several maps by a Cartographer "Nicolaus Germanus (15th cent.)". If you search NYPL for "map" you'll find them, for example "Map of Europe, Africa, the Mediterranean, and Asia. Personifications of the winds. Full gold border." - his name is listed as "Cartographer" under the [more] link. But if you search for "Nicolaus" or "Germanus" or "Nicolaus Germanus (15th cent.)" for "Cartographer" you won't get any hits.
I was able to reproduce this report. It also seems that if you search for "Editors" that the search does work properly. So it may be just the MESA specific Role values that are not functioning properly.
Searching by Role requires content to search beyond the tag. But it doesn't seem to be working. the NYPL collection has several maps by a Cartographer "Nicolaus Germanus (15th cent.)". If you search NYPL for "map" you'll find them, for example "Map of Europe, Africa, the Mediterranean, and Asia. Personifications of the winds. Full gold border." - his name is listed as "Cartographer" under the [more] link. But if you search for "Nicolaus" or "Germanus" or "Nicolaus Germanus (15th cent.)" for "Cartographer" you won't get any hits.