First, check the Ongoing Issues board here to see if the issue is already reported and under investigation.
Second use the search bar to search the Community for your issue. Odds are someone has already reported it in the Help boards. If so, reply in that thread and provide as much information as possible. It will be moved to the Ongoing Issues board if more than one user reports it.
When posting please provide the following information:
If no one has reported an issue like the one you're experiencing, navigate to the relevant forum for your device in our Help boards section and post a new thread there.