The Pokémon GO Plus watch was born to make it easier for trainers to catch Pokémon and spin at PokéStops. There was a bit of a catch, though, trainers are only able to catch already caught Pokémon.
Using the Pokemon GO plus watch would take a Pokeball with a 50/50 chance of the encounter Pokémon either being captured or fleeing. After catching a Pokémon you would receive the normal amount of experience, candies, and stardust. However, there seems to be a bug with receiving stardust.
If this happens to you, don’t worry as there are a few solutions in order to fix this frustrating, yet simple bug. If you begin to see you aren’t gaining stardust for catching Pokémon with the Pokémon GO Plus. Simply restart the app on your phone. You should start to see the bug had been fixed. If not, well, you might need to try some of these suggestions.
Wait patiently for the watch to update. It might take a bit more time than one would want to wait, however, there may be no other option. You could also try hatching an egg, or even catching a Pokémon using the actual application.