Match the edition first
PC multiplayer is separate from console multiplayer. For the PC Legacy-to-Enhanced route, Rockstar retains the Legacy profile after migration, but subsequent progress is not synchronized between the two. PC-to-console and console-to-PC migration are not supported by that process. Read the confirmation screen before creating a new character over an occupied slot.
Secure the account
Verify the email address on the Rockstar account and enable 2-Step Verification through Account, Manage Account, then Security. Use an authenticator you can retain access to. Keep the password and authentication codes private; a service offering to recover or boost an account does not need legitimate access to your login.
When something goes wrong
Record the platform, edition and exact alert, then use Rockstar Support. Do not unlink and relink accounts as an improvised troubleshooting step: progress and entitlements can depend on the linked identity. For PC anti-cheat launch issues, follow the BattlEye support guidance rather than attempting to bypass it.