If you entered beta testing for a Steam game once, it continues to download beta builds even if you exit all beta programs in the Steam client application.
This beta builds may contain errors like this square on the radar in Fallout 4. To return Fallout 4 from beta to stable build without redownloading the full game, navigate to this folder, open this file in any editor and remove this line. Don’t forget to save the file, then go to Fallout 4 options in the Steam Client and check the game cache. It will redownload certain files, and your copy of Fallout 4 will stop being a beta. This method works for any game, you only need to edit the corresponding file in steamapps folder and check the game cache afterwards. The game ID in the filename can be obtained from the game link in the Steam store.