vendor not being able to register despite unique credentials

Describe the bug
as soon as you register the vendor an alert is prompted that already a vendor is registered with this email.

To Reproduce
Steps to reproduce the behavior:

Go to vendors
Click on add new
enter details
See error
Expected behavior
if there is an account on that mail it should be shown in the grid view

Screenshots
image

Desktop (please complete the following information):

OS: Windows
Browser Chrome
Version 122.0.6261.95 (Official Build) (64-bit)

Start at the vendors flow, especially Add New and the vendor grid behavior described in the reproduction steps. Trace the unique-email validation and verify both outcomes: a vendor with unique credentials registers successfully, while an existing account is shown in the grid rather than producing a misleading duplicate alert.

Written by the indexing model from the issue text.