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 by reproducing the vendor registration flow from the Vendors screen: choose Add New and submit unique credentials in Chrome on Windows. Inspect the registration behavior and the vendor grid response to determine why the duplicate-email alert appears; done means a unique vendor registers successfully and an existing account is shown in the grid.

Written by the indexing model from the issue text.