This happens often especially when artists release music under the exact same name, as it is difficult for a store's algorithms to tell the difference between an artist named Sam from the UK and a Sam from the USA.
Before creating your first release we recommend checking to see that no one is releasing music under the name you intend to, and to come up with a unique artist name if so. It's also a good idea to claim or verify your artist profile on the stores - read how to do that on Spotify and Apple Music.
We send all information to the stores exactly as you enter it when creating your release, and so any mixups are unfortunately an issue in the store's systems - but not to worry! The steps to getting your music on the correct profile are very simple.
Note: Some stores are also capable of directly helping with mapping issues, such as Spotify and Amazon.