My brother uses my iPhone as much as I do, Only my face is registered, but then also his face can unlock the phone.
When I delete face data and reset it, for a couple or more days, his face cannot unlock it but then again starts recognising his face. This does not happen in any other Android phone because he does not look like me.
I am okay with it, but this is not correct. Something is wrong with Face ID.
iPhone 11
This is expected.
To quote Apple, emboldening mine:
The probability that a random person in the population could look at your iPhone or iPad Pro and unlock it using Face ID is approximately 1 in 1,000,000 with a single enrolled appearance. As an additional protection, Face ID allows only five unsuccessful match attempts before a passcode is required. The statistical probability is different for twins and siblings that look like you and among children under the age of 13, because their distinct facial features may not have fully developed. If you're concerned about this, we recommend using a passcode to authenticate.
About Face ID advanced technology - Apple Support
As stated, if you are concerned about security, you can shut off FaceID and use a passcode instead.
This is expected.
To quote Apple, emboldening mine:
The probability that a random person in the population could look at your iPhone or iPad Pro and unlock it using Face ID is approximately 1 in 1,000,000 with a single enrolled appearance. As an additional protection, Face ID allows only five unsuccessful match attempts before a passcode is required. The statistical probability is different for twins and siblings that look like you and among children under the age of 13, because their distinct facial features may not have fully developed. If you're concerned about this, we recommend using a passcode to authenticate.
About Face ID advanced technology - Apple Support
As stated, if you are concerned about security, you can shut off FaceID and use a passcode instead.
Does your brother know your passcode? If so, change it and do not share.
Was your brother present when you established Face ID? If so, re-establish Face ID, with no one else in the room?
Were you in the room when your brother unlocked the phone?
Okay, now I am the brother writing. I know the passcode, and I need it. I am seriously saying that I never put my face ID in the phone. We tried resetting the Face ID (without me in the room) many times. It worked, but only for a day or two.
If both of you know the passcode, Face ID is irrelevant. If you wish to actually use the security capability of the device, do not share the passcode with anyone.
Face ID security exploit.
