For the past few months, Samsung Gear S3 owners have been facing an issue where-in sending a text message or replying to one through voice input didn't work. Affected users say they get a "Voice input fail" error message .
The problem seems to be US-specific, rearing its ugly head on units with input language set to US English. Some of those facing the issue have suggested workarounds like using UK English as input language, but that has only limited success.
It's worth mentioning that S Voice isn't affected. Although the problem was acknowledged by a company representative in the official Samsung forums, it's yet to be fixed.