I got a unknown friend when go on the profile doesn't show the the gamertag

You’re welcome, thanks for your cooperation on this one

Don't hesitate to reach the community forums if you need help in the future
For now take care and have a good day

Don’t forget to report the problem and be as detailed as possible
In that way the Xbox team can investigate what’s going on

My signed devices are my xbox series x & My xbox one s & my PC desktop

Hi, if you think that someone else is accessing to your account you can change your password and enable two steps verification (if you need to know how to do this, check the article below)

https://support.microsoft.com/en-us/account-bil...

And also you can double check the devices where your account is signed in here:

https://account.microsoft.com/devices

And here:

https://account.live.com/Activity

How to check if no-one has access to my account information