Thanks for reaching out about this here in the Community!
In addition to the steps you've tried so far, we'd also recommend following the steps here to revoke access to any third party apps you don't recognize.
If you're still having troubles after that, we'd suggest following the steps in the support site article @DanifC mentioned including reaching out to us. This way, a member of our support team can take a look behind the scenes for you.
Let us know how you get on! We'll be right here if you need more help.
Have a lovely day 🙂
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