There have been ongoing issues related to OK Google voice prompts on Android devices going on several months now.
AJ from Google finally posted an update in the ongoing Google Web Search Help thread saying a fix has been released and should be available within the upcoming weeks.
AJ wrote:
Hi everyone, thanks for your patience here!We've worked very hard to fix several issues around your voice actions experience, and we're happy to share that the fix for the particular report in this thread should be rolling out in the next Google Search App version (5.8). Once available in the next few weeks, please upgrade your app version to 5.8 and let us know what you think!
If you continue to experience any issues with using "OK Google" or performing actions from lockscreen when 'Personal results' or 'Trusted Voice' is ON in version 5.8+, please let us know. Thank you!
Sadly, there are still mobile searching saying that after they received the update, the fix has not resolved their issues.
Forum discussion at Google Web Search Help.
