Nominatim Search button greyed out

In JOSM when I try to download an "area around places" (File->Download->Download from OSM->Areas around places, the Nominatim server Search text box appears with the Search button greyed out until something is typed into the text box. At least that's how it's supposed to work. However, in my installation, the button remains greyed out after typing something into the text box and I am unable to proceed.

This has been going on for several months, through several re-installations and several JOSM releases. I am running a fully updated Win 10 computer and the latest JOSM version (v.18118). I reported this several weeks ago on the JOSM development site but before anybody could respond, the Nominatim Search began to work normally again. Unfortunately, however, that didn't last long. I'm forced to use Google Maps to find places and grabbing Lat/Lon coordinates for the general area I'm interested in mapping. I plug these into JOSM's Lat/Lon tool to bring focus to my area of interest.

Naturally, I'm wondering how to fix this. I'm also curious to know if others have experienced this problem.

Thanks in advance.