How fun, it was both!
In Nicaragua, it could be C. multiflora:
http://gardenbreizh.org/photos...
Pg. 62:
https://getd.libs.uga.edu/pdfs...
Callisias are not well documented in English in print or visually.
You could improve your chances of solving the mystery if you are able to take some more cuttings and put them in other conditions, to increase chances of seeing whatever bloom it might make, and any other characteristics it might not display for some reason in the singular condition in which it currently resides. Eventually, you should be able to observe/document something definitive/diagnostic.
Searching in another language if you have such a skill could yield more info. In the meantime, I'm as curious as you are! Good luck!
