From Error documentation
If you received this error, it means there is a restriction that prevents you from linking a new platform account if the same platform type was previously linked to your Epic Games account. To resolve this error, you can re-link your original platform account.
"This Epic Account was previously linked to a different external …
There are two reasons that your console account might say it was connected: Here are steps to determine what Epic Games account your console account is linked to: Note: If you do not see a Sign in button, click the avatar at the top of the screen and click Sign Out to ensure you are not signed into the wrong account.