Auth fails to update user phone number under common conditions

[iosephmagno]

Bug report

• I confirm this is a bug with Supabase, not with my own application.
• I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

User phone is not updated correctly under some common conditions.

To reproduce bug, just update use phone number. We are using flutter plugin, but issue will occur with every plugin.

await Supabase.instance.client.auth.updateUser(UserAttributes(phone: phone));
final response = await auth.updateUser(UserAttributes(phone: phone));

As consequence of above code, Supabase sends an OTP code to verify the user request.
However, below issue occurs:

• If user changes his number from numberA to numberB, and numberB was used recently or already used in the past, the OTP code is either not sent or it is sent but the verify will always fail.

To Reproduce

1. Test with one user and two fixed phone numbers (numberA and numberB).
2. Change user's phone number from numberA to numberB and soon after change back user phone number from numberB to numberA. OTP code won't be sent or verification will always fail.
3. If numberB was already used in the past, OTP is not sent or verification fails. Sometimes this error can also be seen on console:

updating 65819238034: AuthRetryableFetchError

Expected behavior

1. User should be able to change his/her phone number smoothly as long as the new phone number is not already assigned to another user inside project's Auth table.
2. User should be able to change phone number from numberA to numberB and back from numberB to numberA. It can happen that user changes his mind soon after making his action and he must be able to reverse his action.

System information

├── supabase_flutter 2.5.6
│   ├── supabase 2.2.2
│   │   ├── functions_client 2.2.0
│   │   ├── gotrue 2.8.1
│   │   ├── postgrest 2.1.2
│   │   ├── realtime_client 2.1.0
│   │   ├── storage_client 2.0.2

CC: @dshukertjr