A number of GTA Online players have reported getting banned, simply for playing Grand Theft Autos story mode following the re-release of the games this month across PS5 and Xbox Series S/X.
Rockstar Games recently upgraded the game with an Expanded and Enhanced version, the new version of the game has been met with criticism from fans who claim not much has changed apart from the introduction of more bugs.

The original report comes from Rockstar Intel, who warn GTA fans to think before making the switch to story mode as a number of players have reported being falsely banned. If this is the case, it means that players should only be launching GTA Online from the main menu to avoid any potential issues.
It is currently unclear as to why this is actually happening, but we do know that these bans are also related to Red Dead Online, as it is attached to the IP address rather than the physical account.
Rockstar Games are yet to address these concerns up to now, however in the meantime its probably wise for players to avoid opening GTA Online while in the midst of GTA 5 story mode.